docs: def get_proxy_manager(self, osid=None, implementation=None, version=None):
          """Finds, loads and instantiates providers of OSID managers.
  
          Providers must conform to an ``OsidManager`` interface. The
          interfaces are defined in the OSID enumeration. For all OSID
          requests, an instance of ``OsidManager`` that implements the
          ``OsidManager`` interface is returned. In bindings where
          permitted, this can be safely cast into the requested manager.
  
          arg:    osid (osid.OSID): represents the OSID
          arg:    implementation (string): the name of the implementation
          arg:    version (osid.installation.Version): the minimum
                  required OSID specification version
          return: (osid.OsidProxyManager) - the manager of the service
          raise:  ConfigurationError - an error in configuring the
                  implementation
          raise:  NotFound - the implementation class was not found
          raise:  NullArgument - ``implementation`` or ``version`` is
                  ``null``
          raise:  OperationFailed - unable to complete request
          raise:  Unsupported - ``implementation`` does not support the
                  requested OSID
          *compliance: mandatory -- This method must be implemented.*
          *implementation notes*: After finding and instantiating the
          requested ``OsidManager,`` providers must invoke
          ``OsidManager.initialize(OsidRuntimeManager)`` where the
          environment is an instance of the current environment that
          includes the configuration for the service being initialized.
          The ``OsidRuntimeManager`` passed may include information useful
          for the configuration such as the identity of the service being
          instantiated.
  
          """
          # This implementation assumes that all osid impls reside as seperate
          # packages in the dlkit library, so that for instance the proxy manager for an
          # OSID = 'osidpackage' in an implementation named 'impl_name' manager can
          # be found in the python path for the module: dlkit.impl_name.osid.managers
          # Also this implementation currently ignores the OSID specification version.
          try:
              manager_module = import_module('dlkit.' + implementation + '.' + osid.lower() + '.managers')
          except ImportError:
              raise NotFound()
          try:
              proxy_manager = getattr(manager_module, osid.title() + 'ProxyManager')
          except AttributeError:
              raise Unsupported()
          return proxy_manager