docs: def label_weight(base, label_name=None, children=[], parents=[],
                   dependencies=[]):
      """
      Function that returns a Formatoption class for modifying the fontweight
  
      This function returns a :class:`~psyplot.plotter.Formatoption` instance
      that modifies the weight of the given `base` formatoption
  
      Parameters
      ----------
      base: Formatoption
          The base formatoption instance that is used in the
          :class:`psyplot.Plotter` subclass to create the label. The instance
          must have a ``texts`` attribute which stores all the
          :class:`matplotlib.text.Text` instances.
      label_name: str
          The name of the label to use in the documentation. If None,
          it will be ``key``, where ``key`` is the
          :attr:`psyplot.plotter.Formatoption.key`` attribute of `base`
      children: list of str
          The childrens of the resulting formatoption class (besides the `base`
          formatoption which is included anyway)
      parents: list of str
          The parents of the resulting formatoption class (besides the `base`
          the properties formatoption from `base` (see :func:`label_props`))
      dependencies: list of str
          The dependencies of the formatoption
  
      Returns
      -------
      Formatoption
          The formatoption instance that modifies the fontweight of `base`
  
      See Also
      --------
      label_size, label_props, Figtitle, Title"""
      label_name = label_name or base.key
      cl_children = children
      cl_parents = parents
      cl_dependencies = dependencies
  
      class LabelWeight(Formatoption):
          __doc__ = """
          Set the fontweight of the %s
  
          Possible types
          --------------
          %%(fontweights)s
  
          See Also
          --------
          %s, %s, %s""" % (label_name, base.key, base.key + 'size',
                           base.key + 'props')
          children = [base.key] + \
              cl_children
          parent = [base.key + 'props'] + cl_parents
          dependencies = cl_dependencies
  
          group = 'labels'
  
          name = 'Font weight of ' + (base.name or base.key)
  
          def update(self, value):
              for text in getattr(self, base.key).texts:
                  text.set_weight(value)
  
          def get_fmt_widget(self, parent, project):
              """Get a widget with the different font weights"""
              from psy_simple.widgets.texts import FontWeightWidget
              return FontWeightWidget(
                  parent, self, next(iter(getattr(self, base.key).texts), None),
                  base)
  
      return LabelWeight(base.key + 'weight')