parameters: (self, field)
docstring: Instantiates this object with the specified attributes.
  
          `field` is the name of the field by which to group the result set.
docstring_summary: Instantiates this object with the specified attributes.
docstring_tokens: Instantiates this object with the specified attributes .
function: def __init__(self, field):
          """Instantiates this object with the specified attributes.
  
          `field` is the name of the field by which to group the result set.
  
          """
          self.field = field
function_tokens: def __init__ ( self , field ) : self . field = field