code: function createProgram (gl, vertexShader, fragmentShader) {
  
    // Create a program.
    const program = gl.createProgram();
  
    // Attach the shaders.
    gl.attachShader(program, vertexShader);
    gl.attachShader(program, fragmentShader);
  
    // Link the program.
    gl.linkProgram(program);
  
    // Check if it linked.
    const success = gl.getProgramParameter(program, gl.LINK_STATUS);
  
    if (!success && !gl.isContextLost()) {
      // Something went wrong with the link
      const infoLog = gl.getProgramInfoLog(program);
  
      console.error(`WebGL program filed to link:\n${infoLog}`);
    }
  
    return program;
  }
docs: Creates a program from 2 shaders.
  
  @param {!WebGLRenderingContext} gl The WebGL context.
  @param {!WebGLShader} vertexShader A vertex shader.
  @param {!WebGLShader} fragmentShader A fragment shader.
  @return {!WebGLProgram} A program.
  @memberof WebGLRendering