code: function getBytesPerElementForInternalFormat(internalFormat, type) {
    const info = textureInternalFormatInfo[internalFormat];
    if (!info) {
      throw "unknown internal format";
    }
    const bytesPerElement = info.bytesPerElementMap[type];
    if (bytesPerElement === undefined) {
      throw "unknown internal format";
    }
    return bytesPerElement;
  }
docs: Gets the number of bytes per element for a given internalFormat / type
  @param {number} internalFormat The internalFormat parameter from texImage2D etc..
  @param {number} type The type parameter for texImage2D etc..
  @return {number} the number of bytes per element for the given internalFormat, type combo
  @memberOf module:twgl/textures