<p>Such values do not represent characters by themselves,
but are used in the representation of
<a href="#supplementary">supplementary characters</a>
in the UTF-16 encoding.
@param ch the {@code char} value to be tested.
@return {@code true} if the {@code char} value is between
{@link #MIN_HIGH_SURROGATE} and
{@link #MAX_HIGH_SURROGATE} inclusive;
{@code false} otherwise.
@see Character#isLowSurrogate(char)
@see Character.UnicodeBlock#of(int)
Determines if the given {@code char} value is a <a href="http://www.unicode.org/glossary/#high_surrogate_code_unit"> Unicode high-surrogate code unit</a> (also known as <i>leading-surrogate code unit</i>).
<p>Such values do not represent characters by themselves, but are used in the representation of <a href="#supplementary">supplementary characters</a> in the UTF-16 encoding.
@param ch the {@code char} value to be tested. @return {@code true} if the {@code char} value is between {@link #MIN_HIGH_SURROGATE} and {@link #MAX_HIGH_SURROGATE} inclusive; {@code false} otherwise. @see Character#isLowSurrogate(char) @see Character.UnicodeBlock#of(int)