code: def add_def(self, variable, location, size_threshold=32):
          
  
          new_defs_added = False
  
          if isinstance(variable, SimRegisterVariable):
              if variable.reg is None:
                  l.warning('add_def: Got a None for a SimRegisterVariable. Consider fixing.')
                  return new_defs_added
  
              size = min(variable.size, size_threshold)
              offset = variable.reg
              while offset < variable.reg + size:
                  if location not in self._register_map[offset]:
                      new_defs_added = True
                  self._register_map[offset].add(location)
                  offset += 1
  
              self._defs[variable].add(location)
  
          elif isinstance(variable, SimMemoryVariable):
              size = min(variable.size, size_threshold)
              offset = variable.addr
              while offset < variable.addr + size:
                  if location not in self._memory_map[offset]:
                      new_defs_added = True
                  self._memory_map[offset].add(location)
                  offset += 1
  
              self._defs[variable].add(location)
  
          else:
              l.error('Unsupported variable type "%s".', type(variable))
  
          return new_defs_added
docs: Add a new definition of variable.
  
          :param SimVariable variable: The variable being defined.
          :param CodeLocation location: Location of the varaible being defined.
          :param int size_threshold: The maximum bytes to consider for the variable.
          :return: True if the definition was new, False otherwise
          :rtype: bool