Summary
-------
Add a new instance method to `java.lang.String` that returns true
if the string is empty or contains only white space, where white space
is defined as any codepoint that returns true when passed to
Character#isWhitespace(int).
Problem
-------
A traditional solution requires the construction of a new string by
stripping the instance string of leading or trailing white space.
```
Ex 1.
// true iff is empty or only contains white space
boolean blank = string.trim().isEmpty();
```
In Java 8, the in place solution is awkward in its complexity.
```
Ex. 2
// true iff is empty or only contains white space
boolean blank = string.codePoints().allMatch(Character::isWhitespace);
```
Solution
--------
The introduction of a new method that avoids any object construction
and reduces use complexity.
```
Ex 3.
// true iff is empty or only contains white space
boolean blank = string.isBlank();
```
Specification
-------------
```
/**
* Returns {@code true} if the string is empty or contains only
* {@link Character#isWhitespace(int) white space} codepoints,
* otherwise {@code false}.
*
* @return {@code true} if the string is empty or contains only
* {@link Character#isWhitespace(int) white space} codepoints,
* otherwise {@code false}
*
* @see Character#isWhitespace(int)
*
* @since 11
*/
public boolean isBlank() {
```