Returns this JSON value as a
long value, assuming that this value represents a JSON number that can be interpreted as Java
long. If this is not the case, an exception is thrown.
To be interpreted as Java long, the JSON number must neither contain an exponent nor a fraction part. Moreover, the number must be in the Long range.
@return this value as
long
@throws UnsupportedOperationException if this value is not a JSON number
@throws NumberFormatException if this JSON number can not be interpreted as
long value