class_docstr: Data manager for all plugin.
      
docstr: Get reservoir by plugin as key.
  
  Args:
      plugin: Key to get one reservoir bucket for one specified plugin.
  
  Returns:
      Reservoir bucket for plugin.
docstr_tok: ["Get","reservoir","by","plugin","as","key",".","Args",":","plugin",":","Key","to","get","one","reservoir","bucket","for","one","specified","plugin",".","Returns",":","Reservoir","bucket","for","plugin","."]
code: def get_reservoir(self, plugin):
      """Get reservoir by plugin as key.
  
      Args:
          plugin: Key to get one reservoir bucket for one specified plugin.
  
      Returns:
          Reservoir bucket for plugin.
      """
      with self._mutex:
          if plugin not in self._reservoirs.keys():
              raise KeyError("Key %s not in reservoirs." % plugin)
          return self._reservoirs[plugin]
  
imports: import collections
  import random
  import threading
label_desc: Use image node_id 3 for calling the DataManager obj's underlying member method code with example usage: obj.get_reservoir(plugin) and returns: self