Check if this genomic interval is on the negative strand.

    :return: True if this element is on the negative strand

def isNegativeStrand(self):
    """
    Check if this genomic interval is on the negative strand.

    :return: True if this element is on the negative strand
    """
    if self.strand is None and self.DEFAULT_STRAND == self.NEGATIVE_STRAND:
      return True
    return self.strand == self.NEGATIVE_STRAND