docs: def populate(self, obj):
          """ Populate
          
          Query mongo to get information about the obj if it exists
          
          Args:
              obj (AtlasServiceBinding.Binding or AtlasServiceInstance.Instance): instance or binding
          
          Raises:
              ErrStorageTypeUnsupported: Type unsupported.
              ErrStorageMongoConnection: Error during MongoDB communication.
          """
          
          # query
          if type(obj) is AtlasServiceInstance.Instance:
              query = { "instance_id" : obj.instance_id, "binding_id" : { "$exists" : False } }
          elif type(obj) is AtlasServiceBinding.Binding:
              query = { "binding_id" : obj.binding_id, "instance_id" : obj.instance.instance_id }
          else:
              raise ErrStorageTypeUnsupported(type(obj))
          
          # find
          try:
              result = self.broker.find_one(query)
          except:
              raise ErrStorageMongoConnection("Populate Instance or Binding")
          
          if result is not None:
              obj.parameters = result["parameters"]
              
              # Flags the obj to provisioned
              obj.provisioned = True
          else:
              # New
              obj.provisioned = False