Returns the largest (closest to positive infinity)
{@code double} value that is less than or equal to the
argument and is equal to a mathematical integer. Special cases:
<ul><li>If the argument value is already equal to a
mathematical integer, then the result is the same as the
argument. <li>If the argument is NaN or an infinity or
positive zero or negative zero, then the result is the same as
the argument.</ul>
@param a a value.
@return the largest (closest to positive infinity)
floating-point value that less than or equal to the argument
and is equal to a mathematical integer.
Returns the largest (closest to positive infinity) {@code double} value that is less than or equal to the argument and is equal to a mathematical integer. Special cases: <ul><li>If the argument value is already equal to a mathematical integer, then the result is the same as the argument. <li>If the argument is NaN or an infinity or positive zero or negative zero, then the result is the same as the argument.</ul>
@param a a value. @return the largest (closest to positive infinity) floating-point value that less than or equal to the argument and is equal to a mathematical integer.