code: def add_default_envs(self):
      if self._cpu:
          self.add_env("MKL_NUM_THREADS", str(self._cpu))
          self.add_env("MARS_CPU_TOTAL", str(self._cpu))
          self.add_env("MARS_USE_PROCESS_STAT", "1")
  
      if self._memory:
          self.add_env("MARS_MEMORY_TOTAL", str(int(self._memory)))
  
      if self._modules:
          self.add_env("MARS_LOAD_MODULES", ",".join(self._modules))
  
      if self._path_environ:
          self.add_env("MARS_YARN_PATH", self._path_environ)
  
      if self._source_path:
          self.add_env("MARS_SOURCE_PATH", self._source_path)
  
imports: import os
  import textwrap
  from urllib.parse import urlparse
  from ...utils import parse_readable_size
label_desc: Use image node_id 2 for calling the MarsServiceConfig obj's underlying member method code with example usage: obj.add_default_envs() without return types