public void setMinSize(final int minSize) {
            this.minSize = minSize;
            final LayoutData layout = (LayoutData) target.getLayoutData();

            // Try resetting the associated widget's size, which will enforce the new minSize value.
            setAssociatedWidgetSize((int) layout.size);
        }
Sets the minimum allowable size for the given widget.
<p>
<p>
Its associated splitter cannot be dragged to a position that would make
it smaller than this size. This method has no effect for the
{@link DockLayoutPanel.Direction#CENTER} widget.
</p>

@param child   the child whose minimum size will be set
@param minSize the minimum size for this widget
stroom-core-client-widget/src/main/java/com/google/gwt/user/client/ui/MySplitLayoutPanel.java