class_docstr: Labelled arrow for use as a quiver plot scale key.
class_docstr_tok: ["Labelled","arrow","for","use","as","a","quiver","plot","scale","key","."]
code: def _init(self):
      if True:  # not self._initialized:
          if not self.Q._initialized:
              self.Q._init()
          self._set_transform()
          _pivot = self.Q.pivot
          self.Q.pivot = self.pivot[self.labelpos]
          # Hack: save and restore the Umask
          _mask = self.Q.Umask
          self.Q.Umask = ma.nomask
          self.verts = self.Q._make_verts(
              np.array([self.U]), np.zeros((1,)), self.angle
          )
          self.Q.Umask = _mask
          self.Q.pivot = _pivot
          kw = self.Q.polykw
          kw.update(self.kw)
          self.vector = mcollections.PolyCollection(
              self.verts,
              offsets=[(self.X, self.Y)],
              transOffset=self.get_transform(),
              **kw,
          )
          if self.color is not None:
              self.vector.set_color(self.color)
          self.vector.set_transform(self.Q.get_transform())
          self.vector.set_figure(self.get_figure())
          self._initialized = True
  
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import six
  import math
  import weakref
  import numpy
  from numpy import ma
  import matplotlib.collections
  import matplotlib.transforms
  import matplotlib.text
  import matplotlib.artist
  from matplotlib.artist import allow_rasterization
  from matplotlib import docstring
  import matplotlib.font_manager
  from matplotlib.cbook import delete_masked_points
  from matplotlib.patches import CirclePolygon
label_desc: Use image node_id 3 for calling the QuiverKey obj's underlying member method code with example usage: obj._init() without return types