code: def _is_entity(bpe):
      
      if isinstance(bpe, _bp('Protein')) or \
          isinstance(bpe, _bpimpl('Protein')) or \
          isinstance(bpe, _bp('SmallMolecule')) or \
          isinstance(bpe, _bpimpl('SmallMolecule')) or \
          isinstance(bpe, _bp('Complex')) or \
          isinstance(bpe, _bpimpl('Complex')) or \
          isinstance(bpe, _bp('Rna')) or \
          isinstance(bpe, _bpimpl('Rna')) or \
          isinstance(bpe, _bp('RnaRegion')) or \
          isinstance(bpe, _bpimpl('RnaRegion')) or \
          isinstance(bpe, _bp('DnaRegion')) or \
          isinstance(bpe, _bpimpl('DnaRegion')) or \
          isinstance(bpe, _bp('PhysicalEntity')) or \
          isinstance(bpe, _bpimpl('PhysicalEntity')):
          return True
      else:
          return False
docs: Return True if the element is a physical entity.