public Layer setDepth(float depth) {
    float oldDepth = this.depth;
    if (depth != oldDepth) {
      this.depth = depth;
      if (parent != null) parent.depthChanged(this, oldDepth);
    }
    return this;
  }
public Layer setDepth ( float depth ) { float oldDepth = this . depth ; if ( depth != oldDepth ) { this . depth = depth ; if ( parent != null ) parent . depthChanged ( this , oldDepth ) ; } return this ; }
Sets the depth of this layer.
<p>
Within a single {@link GroupLayer}, layers are rendered from lowest depth to highest depth.

@return a reference to this layer for call chaining.