end property
The offset at which stop 1.0 of this LinearSteps is placed.
If this is an Alignment, then it is expressed as a vector from
coordinate (0.0, 0.0), in a coordinate space that maps the center of the
paint box at (0.0, 0.0) and the bottom right at (1.0, 1.0).
For example, an end offset of (1.0, 0.0)
is half way down the right side of the box.
It can also be an AlignmentDirectional, where the start is the left
in left-to-right contexts and the right in right-to-left contexts.
If a text-direction-dependent value is provided here,
then the createShader method will need to be given a TextDirection.
Copied from LinearGradient.
Implementation
final AlignmentGeometry end;