code: def replace_uri(rdf, fromuri, touri):
      
      replace_subject(rdf, fromuri, touri)
      replace_predicate(rdf, fromuri, touri)
      replace_object(rdf, fromuri, touri)
docs: Replace all occurrences of fromuri with touri in the given model.
  
      If touri is a list or tuple of URIRef, all values will be inserted.
      If touri=None, will delete all occurrences of fromuri instead.