code: def lookup(self, dotted_path, lineno=None):
          
          rv = None
          try:
              rv = rustcall(
                  _lib.lsm_proguard_mapping_convert_dotted_path,
                  self._get_ptr(),
                  dotted_path.encode('utf-8'), lineno or 0)
              return _ffi.string(rv).decode('utf-8', 'replace')
          finally:
              if rv is not None:
                  _lib.lsm_buffer_free(rv)
docs: Given a dotted path in the format ``class_name`` or
          ``class_name:method_name`` this performs an alias lookup.  For
          methods the line number must be supplied or the result is
          unreliable.