2-Collection_Containers.adoc file updated for adding IntInterval Docu…

…mentation.

docs/2-Collection_Containers.adoc

@@ -951,11 +951,64 @@ IntArrayList listFromIntIterable = IntArrayList.newListWith(IntHashSet.newSetWit
 
 An *IntInterval* is a range of **int**s that may be iterated over using a step value.
 (Similar to *Interval*, but uses primitive ints instead of the wrapper *Integers*.)
+All arguments are inclusive in methods of IntInterval.
 
+As *IntInterval* implements *ImmutableIntList*, you can pass it in any method or constructor argument which accept *ImmutableIntList*.
 [source,java]
 ----
-Assert.assertEquals(IntLists.mutable.with(1, 2, 3), IntInterval.oneTo(3));
-Assert.assertEquals(IntLists.mutable.with(1, 3, 5), IntInterval.oneToBy(5, 2));
+Assertions.assertInstanceOf(ImmutableIntList.class, IntInterval.oneTo(5));
+----
+
+.There are different ways you can generate interval of numbers using *IntInterval*, which are listed below.
+- You can initialize IntInterval using constructor argument which accept from, to and steps.
+- You can initialize IntInterval using static factory methods.
+[source,java]
+----
+// Generate interval of numbers from 1 to 5, with the default step value of 1
+ImmutableIntList expected = IntLists.immutable.with(1, 2, 3, 4, 5);
+Assertions.assertEquals(expected, IntInterval.fromTo(1, 5));
+
+// Generate interval of numbers from 1 to 10, with providing steps value as method argument
+ImmutableIntList expected = IntLists.immutable.with(1, 4, 7, 10);
+Assertions.assertEquals(expected, IntInterval.fromToBy(1, 10, 3));
+
+// from method is used to generate interval with only one number which is provided as method argument
+ImmutableIntList expected = IntLists.immutable.with(10);
+Assertions.assertEquals(expected, IntInterval.from(10));
+
+// Generate interval of even numbers, here steps value can be 2 or -2, based on following condition [to > from ? 2 : -2]
+ImmutableIntList expected = IntLists.immutable.with(2, 4, 6);
+Assertions.assertEquals(expected, IntInterval.evensFromTo(2, 6));
+
+ImmutableIntList expected = IntLists.immutable.with(6, 4, 2);
+Assertions.assertEquals(expected, IntInterval.evensFromTo(6, 2));
+
+// Generate interval of odd numbers, here steps value can be 2 or -2, based on following condition [to > from ? 2 : -2]
+ImmutableIntList expected = IntLists.immutable.with(1, 3, 5);
+Assertions.assertEquals(expected, IntInterval.oddsFromTo(1, 5));
+
+ImmutableIntList expected = IntLists.immutable.with(5, 3, 1);
+Assertions.assertEquals(expected, IntInterval.oddsFromTo(5, 1));
+
+// Generate interval of numbers from 1 to 5, with the default step value of 1
+ImmutableIntList expected = IntLists.immutable.with(1, 2, 3, 4, 5);
+Assertions.assertEquals(expected, IntInterval.oneTo(5));
+
+// Generate interval of numbers from 1 to 9, with providing step value as a method argument
+ImmutableIntList expected = IntLists.immutable.with(1, 3, 5, 7, 9);
+Assertions.assertEquals(expected, IntInterval.oneToBy(10, 2));
+
+// zero is used to create interval with only one number [0]
+ImmutableIntList expected = IntLists.immutable.with(0);
+Assertions.assertEquals(expected, IntInterval.zero());
+
+// Generate interval of numbers from 0 to 4, with the default step value of 1
+ImmutableIntList expected = IntLists.immutable.with(0, 1, 2, 3, 4);
+Assertions.assertEquals(expected, IntInterval.zeroTo(4));
+
+// Generate interval of numbers from 0 to 4, with providing step value as a method argument
+ImmutableIntList expected = IntLists.immutable.with(0, 2, 4);
+Assertions.assertEquals(expected, IntInterval.zeroToBy(4, 2));
 ----
 
 === Primitive sets