code: function isEnclosedY(yp, y1, y2) {
    if ((y1 < yp && yp < y2) || (y2 < yp && yp < y1)) {
      return true;
    }
  
    return false;
  }
docs: Returns true if the y-position yp is enclosed within y-positions y1 and y2.
  @private
  @method
  @name isEnclosedY
  
  @param {number} yp The y position of point p.
  @param {number} y1 The y position of point 1.
  @param {number} y2 The y position of point 2.
  @returns {boolean} True if the y-position yp is enclosed within y-positions y1 and y2.