Return the set of knowledgebase path dependencies required by the parser.

  Args:
    rdf_artifact: RDF artifact object.

  Returns:
    A set of strings for the required kb objects e.g.
    ["users.appdata", "systemroot"]

def GetArtifactParserDependencies(rdf_artifact):
  """Return the set of knowledgebase path dependencies required by the parser.

  Args:
    rdf_artifact: RDF artifact object.

  Returns:
    A set of strings for the required kb objects e.g.
    ["users.appdata", "systemroot"]
  """
  deps = set()
  processors = parser.Parser.GetClassesByArtifact(rdf_artifact.name)
  for p in processors:
    deps.update(p.knowledgebase_dependencies)
  return deps