'Return a list of column indeces for \'chromCol\', \'startCol\', \'endCol\' from
a source representing a genomic region.
:param check: if True will raise a ValueError if any were not found.
:type check: bool
:raises ValueError: if check is `True` and one or more indeces were not found.
:returns: list of column indeces for the named columns.'

def get_genomic_region_indeces(self, check=False):

    region_column_names = ('chromCol', 'startCol', 'endCol')
    region_indices = [self.get_metadata_column_index_by_name(name) for name in region_column_names]
    if (check and (not all(((_ is not None) for _ in region_indices)))):
        raise ValueError(('Could    not    determine    proper    column    indices    for    chrom,    start,    end:    %s' % str(region_indices)))
    return region_indices
