text: import { fromJS } from 'immutable'
  import wallColor from '/src/constants/wall-color'
  import wallWidth from '/src/constants/wall-width'
  
  // Represents the directions to draw a vertical line (wall)
  // as an SVG path element.
  //
  // For example, verticalWall({ x: 0, y: 10, length: 20 })
  // is equivalent to <path d="M 0,10 v 20"/>
  export default ({
    x,
    y,
    length = 10,
    color = wallColor,
    width = wallWidth
  }) => {
    return fromJS({
      color,
      width,
      drawCommands: [
        { command: 'M', x, y },
        { command: 'v', length }
      ]
    })
  }
  