text: function alpha(value, color) {
      return value << 24 | (color & 0x00FFFFFF);
  }
  
  function argb(a, r, g, b) {
      return a << 24 | r << 16 | g << 8 | b;
  }
  
  function assert(condition) {
      if (!condition) debugger;
  }
  
  function isAlpha(code) {
      return (code > 64 && code < 91) // upper alpha (A-Z)
          || (code > 96 && code < 123); // lower alpha (a-z)
  }
  
  function isArray(a) {
      return a.constructor === Array;
  }
  
  function rgb(r, g, b) {
      return 0xFF << 24 | r << 16 | g << 8 | b;
  }
  