class_docstr: Data manager for all plugin.
      
docstr: Add reservoir to reservoirs.
  
  Every reservoir is attached to one plugin.
  
  Args:
      plugin: Key to get one reservoir bucket for one specified plugin.
docstr_tok: ["Add","reservoir","to","reservoirs",".","Every","reservoir","is","attached","to","one","plugin",".","Args",":","plugin",":","Key","to","get","one","reservoir","bucket","for","one","specified","plugin","."]
code: def add_reservoir(self, plugin):
      """Add reservoir to reservoirs.
  
      Every reservoir is attached to one plugin.
  
      Args:
          plugin: Key to get one reservoir bucket for one specified plugin.
      """
      with self._mutex:
          if plugin not in self._reservoirs.keys():
              self._reservoirs.update(
                  {
                      plugin: Reservoir(
                          max_size=DEFAULT_PLUGIN_MAXSIZE[plugin]
                      )
                  }
              )
  
imports: import collections
  import random
  import threading
label_desc: Use image node_id 2 for calling the DataManager obj's underlying member method code with example usage: obj.add_reservoir(plugin) without return types