code: func ParseEnv(spec []string, defaultReader io.Reader) ([]v1.EnvVar, []string, error) {
  	return parseIntoEnvVar(spec, defaultReader, "environment variable")
  }
docs: // ParseEnv parses the elements of the first argument looking for environment variables in key=value form and, if one of those values is "-", it also scans the reader.
  // The same environment variable cannot be both modified and removed in the same command.