code: function( styles, ctx ){
  
              ctx = ctx || this.ctx;
  
              if ( Physics.util.isObject(styles) ){
  
                  styles.strokeStyle = styles.lineWidth ? styles.strokeStyle : 'rgba(0,0,0,0)';
                  Physics.util.extend(ctx, styles);
  
              } else {
  
                  ctx.fillStyle = ctx.strokeStyle = styles;
                  ctx.lineWidth = 1;
              }
          }
docs: CanvasRenderer#setStyle( styles[, ctx] )
  - styles (Object|String): Styles to set on the canvas context
  - ctx (Canvas2DContext): The canvas context
  
  Set styles on the specified canvas context (or main context).