TST ensure correct operation of has_sorted_indices
FIX use mangled attribute correctly
STY avoid mangled attributes in has_sorted_indices
Merge pull request #3305 from jnothman/test_has_sorted_indices

BUG: sparse: ensure correct operation of has_sorted_indices

Fix errors in use of hasattr/getattr/et al. with mangled double-underscore
attribute names, by switching to unmangled names.