code: function asciifyMatrix(pixels, options) {
      let asciifier = new asciifyPixel.Asciifier(options);
  
      options = ul.merge(options, {
          stringify: true
        , concat: true
      });
  
      if (!Array.isArray(pixels)) {
          return [];
      }
  
      if (!Array.isArray(pixels[0])) {
          pixels = [pixels];
      }
  
      let result = pixels.map(row => {
          return row.map(p => {
              return asciifier.asciify(p);
          });
      });
  
      if (options.stringify !== false) {
          result = asciifyMatrix.stringify(result);
      }
  
      if (options.concat !== false) {
          result = asciifyMatrix.join(result);
      }
  
      return result;
  }
docs: asciifyMatrix
  
  @name asciifyMatrix
  @function
  @param {Matrix} pixels The pixels matrix (array of arrays of pixel objects).
  @param {Object} options An object to pass to `asciify-pixel` extended with the following fields:
  
  - `stringify` (Boolean): If `false`, the pixel objects will not be stringified.
  - `concat` (Boolean): If `false`, the pixel objects will not be joined together.
  
  @return {Matrix|String} The result matrix.