code: def _make_safe_id(self, id):
          
  
          substitutions = {
              '-': '_DASH_',
              '/': '_FSLASH_',
              '\\': '_BSLASH_',
              '(': '_LPAREN_',
              ')': '_RPAREN_',
              '[': '_LSQBKT_',
              ']': '_RSQBKT_',
              ',': '_COMMA_',
              '.': '_PERIOD_',
              "'": '_APOS_'
          }
  
          id = re.sub(r'\(([a-z])\)$', '_\\1', id)
          for symbol, escape in iteritems(substitutions):
              id = id.replace(symbol, escape)
          id = re.sub(r'[^a-zA-Z0-9_]', '', id)
          return id
docs: Returns a modified id that has been made safe for SBML.
  
          Replaces or deletes the ones that aren't allowed.