The below tables show the result for running the implemented bechmark tests.

Asking for element in a random position

Test Identifier	Stream Len	Speed
BenchmarkAtString10-4	10	160 ns/op
BenchmarkAtString100-4	100	229 ns/op
BenchmarkAtString1000-4	1000	211 ns/op
BenchmarkAtString5000-4	5000	156 ns/op

Asking for element in the first position

Test Identifier	Stream Len	Speed
BenchmarkFirstString10-4	10	235 ns/op
BenchmarkFirstString100-4	100	191 ns/op
BenchmarkFirstString1000-4	1000	370 ns/op
BenchmarkFirstString5000-4	5000	259 ns/op

Asking for element in the last position

Test Identifier	Stream Len	Speed
BenchmarkLastString10-4	10	200 ns/op
BenchmarkLastString100-4	100	204 ns/op
BenchmarkLastString1000-4	1000	214 ns/op
BenchmarkLastString5000-4	5000	190 ns/op

Adding a new element in a stream of strings

Test Identifier	Stream Len	Speed
BenchmarkAddString10-4	10	718 ns/op
BenchmarkAddString100-4	100	1276 ns/op
BenchmarkAddString1000-4	1000	7561 ns/op
BenchmarkAddString5000-4	5000	44036 ns/op

Remove an element (that exists) from a stream of strings

Test Identifier	Stream Len	Speed
BenchmarkAddString10-4	10	686 ns/op
BenchmarkAddString100-4	100	850 ns/op
BenchmarkAddString1000-4	1000	2086 ns/op
BenchmarkAddString5000-4	5000	10275 ns/op

Remove an element (that does not exist) from a stream of strings

Test Identifier	Stream Len	Speed
BenchmarkDropString10UnExistingElement-4	10	584 ns/op
BenchmarkDropString100UnExistingElement-4	100	711 ns/op
BenchmarkDropString1000UnExistingElement-4	1000	1393 ns/op
BenchmarkDropString5000UnExistingElement-4	5000	3763 ns/op

Converting a stream of strings in a new stream of strings with uppercase

Test Identifier	Stream Len	Speed
BenchmarkMapString10ToUpper-4	10	1366 ns/op
BenchmarkMapString100ToUpper-4	10	7496 ns/op
BenchmarkMapString1000ToUpper-4	10	79248 ns/op
BenchmarkMapString5000ToUpper-4	10	507272 ns/op

Converting a stream of strings in a new stream of int with the len of all the elements

Test Identifier	Stream Len	Speed
BenchmarkReduceInt10Sum-4	10	324 ns/op
BenchmarkReduceInt100Sum-4	100	629 ns/op
BenchmarkReduceInt1000Sum-4	1000	3782 ns/op
BenchmarkReduceInt5000Sum-4	5000	9533 ns/op

|

Removing from the stream those elements that they're not even

Test Identifier	Stream Len	Speed
BenchmarkFilterNumbers10LenIsEven-4	10	850 ns/op
BenchmarkFilterNumbers100LenIsEven-4	100	1785 ns/op
BenchmarkFilterNumbers1000LenIsEven-4	1000	17190 ns/op
BenchmarkFilterNumbers5000LenIsEven-4	5000	26437 ns/op

Sum the len of all the string elements in a tream

Test Identifier	Stream Len	Speed
BenchmarkReduceString10SumLen-4	10	355 ns/op
BenchmarkReduceString100SumLen-4	100	723 ns/op
BenchmarkReduceString1000SumLen-4	1000	4254 ns/op
BenchmarkReduceString5000SumLen-4	5000	21286 ns/op

Sum all the elments in a stream of ints

Test Identifier	Stream Len	Speed
BenchmarkReduceInt10Sum-4	10	324 ns/op
BenchmarkReduceInt100Sum-4	199	629 ns/op
BenchmarkReduceInt1000Sum-4	1999	3782 ns/op
BenchmarkReduceInt5000Sum-4	5000	9533 ns/op

Iterating over a stream of int and printing the value

Test Identifier	Stream Len	Speed
BenchmarkForEachNumbers10Print-4	10	445 ns/op
BenchmarkForEachNumbers100Print-4	100	647 ns/op
BenchmarkForEachNumbers1000Print-4	1000	2980 ns/op
BenchmarkForEachNumbers5000Print-4	5000	7260 ns/op

Removing duplicated elements in a stream of strings

Test Identifier	Stream Len	Speed
BenchmarkDuplicatedString10-4	10	4695 ns/op
BenchmarkDuplicatedString10-4	100	39628 ns/op
BenchmarkDuplicatedString10-4	1000	413261 ns/op
BenchmarkDuplicatedString10-4	5000	2436386 ns/op

Counting the number of elements in a stream o strings

Test Identifier	Stream Len	Speed
BenchmarkCountString10-4	10	101 ns/op
BenchmarkCountString10-4	100	98.6 ns/op
BenchmarkCountString10-4	1000	108 ns/op
BenchmarkCountString10-4	5000	96.5 ns/op

The searched element is in the first position of the stream of strings

Test Identifier	Stream Len	Speed
BenchmarkContainsString10FirstElement-4	10	284 ns/op
BenchmarkContainsString100FirstElement-4	100	331 ns/op
BenchmarkContainsString1000FirstElement-4	1000	337 ns/op
BenchmarkContainsString5000FirstElement-4	5000	346 ns/op

The searched element is in the last position of the stream of strings

Test Identifier	Stream Len	Speed
BenchmarkContainsString10LastElement-4	10	327 ns/op
BenchmarkContainsString100LastElement-4	100	347 ns/op
BenchmarkContainsString1000LastElement-4	1000	1060 ns/op
BenchmarkContainsString5000LastElement-4	5000	4930 ns/op

The searched element doesn't exist in the stream of strings

Test Identifier	Stream Len	Speed
BenchmarkContainsString10NotFound-4	10	246 ns/op
BenchmarkContainsString100NotFound-4	100	515 ns/op
BenchmarkContainsString1000NotFound-4	1000	1650 ns/op
BenchmarkContainsString5000NotFound-4	5000	8905 ns/op

Reversing sequence of elements in a stream of strings

Test Identifier	Stream Len	Speed
BenchmarkReverseString10-4	10	477 ns/op
BenchmarkReverseString100-4	100	1218 ns/op
BenchmarkReverseString1000-4	1000	7505 ns/op
BenchmarkReverseString5000-4	5000	37553 ns/op

Taking the elements between positions 1 and len-1

Test Identifier	Stream Len	Speed
BenchmarkTakeNumbers1000Between1and9-4	10	326 ns/op
BenchmarkTakeNumbers1000Between1and99-4	100	323 ns/op
BenchmarkTakeNumbers1000Between1and999-4	1000	335 ns/op
BenchmarkTakeNumbers2500etween1and2499-4	5000	321 ns/op

LastIndexOf the first element in the stream

Test Identifier	Stream Len	Speed
BenchmarkLastIndexOfString10FirstElement-4	10	274 ns/op
BenchmarkLastIndexOfString100FirstElement-4	100	325 ns/op
BenchmarkLastIndexOfString1000FirstElement-4	1000	582 ns/op
BenchmarkLastIndexOfString5000FirstElement-4	5000	3832 ns/op

LastIndexOf the last element in the stream

Test Identifier	Stream Len	Speed
BenchmarkLastIndexOfString10LastElement-4	10	275 ns/op
BenchmarkLastIndexOfString100LastElement-4	100	279 ns/op
BenchmarkLastIndexOfString1000LastElement-4	1000	280 ns/op
BenchmarkLastIndexOfString5000LastElement-4	5000	279 ns/op

LastIndexOf a non found element

Test Identifier	Stream Len	Speed
BenchmarkLastIndexOfString10NotFound-4	10	243 ns/op
BenchmarkLastIndexOfString100NotFound-4	100	361 ns/op
BenchmarkLastIndexOfString1000NotFound-4	1000	1433 ns/op
BenchmarkLastIndexOfString5000NotFound-4	5000	7267 ns/op

Repleace element in position 0

Test Identifier	Stream Len	Speed
BenchmarkSetString10-4	10	771 ns/op
BenchmarkSetString100-4	100	1451 ns/op
BenchmarkSetString1000-4	1000	6717 ns/op
BenchmarkSetString5000-4	5000	32890 ns/op

IndexOf the first element in the stream

Test Identifier	Stream Len	Speed
BenchmarkIndexOfString10FirstElement-4	10	275 ns/op
BenchmarkIndexOfString100FirstElement-4	100	277 ns/op
BenchmarkIndexOfString1000FirstElement-4	1000	280 ns/op
BenchmarkIndexOfString5000FirstElement-4	5000	276 ns/op

IndexOf the last element in the stream

Test Identifier	Stream Len	Speed
BenchmarkIndexOfString10LastElement-4	10	273 ns/op
BenchmarkIndexOfString100LastElement-4	100	327 ns/op
BenchmarkIndexOfString1000LastElement-4	1000	764 ns/op
BenchmarkIndexOfString5000LastElement-4	5000	3687 ns/op

IndexOf a non found element

Test Identifier	Stream Len	Speed
BenchmarkIndexOfString10NotFound-4	10	266 ns/op
BenchmarkIndexOfString100NotFound-4	100	337 ns/op
BenchmarkIndexOfString1000NotFound-4	1000	1248 ns/op
BenchmarkIndexOfString5000NotFound-4	5000	7288 ns/op