code: public void setOffset(float offset, final Axis axis) {
          if (!equal(mOffset.get(axis), offset)) {
              mOffset.set(offset, axis);
              if (mContainer != null) {
                  mContainer.onLayoutChanged(this);
              }
          }
      }
docs: Set the amount of offset between child objects and parent.
  @param axis {@link Axis}
  @param offset