code: def get(self, study_id, content=None, schema=None, **kwargs):
          
          if isinstance(study_id, TreeRef):
              return self.get(study_id=study_id.study_id,
                              tree_id=study_id.tree_id,
                              content=content,
                              schema=schema,
                              **kwargs)
          if schema is None:
              schema = create_content_spec(content=content,
                                           repo_nexml2json=self.repo_nexml2json,
                                           **kwargs)
          r = self.get_study(study_id, schema)
          if schema.content == 'study' and schema.format_str == 'nexson':
              return r
          if isinstance(r, dict) and ('data' in r):
              return r['data']
          return r
docs: Syntactic sugar around to make it easier to get fine-grained access
          to the parts of a file without composing a PhyloSchema object.
          Possible invocations include:
              w.get('pg_10')
              w.get('pg_10', 'trees')
              w.get('pg_10', 'trees', format='nexus')
              w.get('pg_10', tree_id='tree3')
          see: