This interface represents the current state of the
selection for any of the components that display a
list of values with stable indices. The selection is
modeled as a set of intervals, each interval represents
a contiguous range of selected list elements.
The methods for modifying the set of selected intervals
all take a pair of indices, index0 and index1, that represent
a closed interval, i.e. the interval includes both index0 and
index1.