Return Python list of (spanner, index) pairs. ‘left’ must be either an Abjad component or None. ‘right’ must be either an Abjad component or None.
If both ‘left’ and ‘right’ are components, then ‘left’ and ‘right’ must be thread-contiguous.
This is a special version of spannertools.get_spanners_that_dominate_components(). This version is useful for finding spanners that dominant a zero-length ‘crack’ between components, as in t[2:2].
Changed in version 2.0: renamed spannertools.get_dominant_between() to spannertools.get_spanners_that_dominate_component_pair().