docstr: Returns a dictionary of environment variables to be set
  
  Parameters
  ----------
  runtime_name : string
      Name of the runtime for which to get the environment
  
  Returns
  -------
  dict[string] -> string
      Environment variables from this metadata provider
code: def get_runtime_environment(self, runtime_name):
      """
      Returns a dictionary of environment variables to be set
  
      Parameters
      ----------
      runtime_name : string
          Name of the runtime for which to get the environment
  
      Returns
      -------
      dict[string] -> string
          Environment variables from this metadata provider
      """
      return {
          "METAFLOW_RUNTIME_NAME": runtime_name,
          "USER": get_username(),
      }
  
imports: import json
  import os
  import re
  import time
  from collections import namedtuple
  from itertools import chain
  from metaflow.exception import MetaflowInternalError, MetaflowTaggingError
  from metaflow.tagging_util import validate_tag
  from metaflow.util import get_username, resolve_identity_as_tuple, is_stringish
label_desc: Use image node_id 8 for calling the MetadataProvider obj's underlying member method code with example usage: obj.get_runtime_environment(runtime_name) and returns: dict