lib/types/mutable-long.js
function MutableLong(b00, b16, b32, b48) {
  // Use an array of uint16
  this._arr = [ b00 & 0xffff, b16 & 0xffff, b32 & 0xffff, b48 & 0xffff ];
}
function MutableLong(b00, b16, b32, b48) {
  // Use an array of uint16
  this._arr = [ b00 & 0xffff, b16 & 0xffff, b32 & 0xffff, b48 & 0xffff ];
}
Constructs a signed int64 representation.
@constructor
@ignore