'Parameters
s : str
a string to be displayed.
textprops : `~matplotlib.font_manager.FontProperties`, optional
multilinebaseline : bool, optional
If `True`, baseline for multiline text is adjusted so that
it is (approximatedly) center-aligned with singleline
text.
minimumdescent : bool, optional
If `True`, the box has a minimum descent of "p".'

def __init__(self, s, textprops=None, multilinebaseline=None, minimumdescent=True):

    if (textprops is None):
        textprops = {}
    if (u'va' not in textprops):
        textprops[u'va'] = u'baseline'
    self._text = mtext.Text(0, 0, s, **textprops)
    OffsetBox.__init__(self)
    self._children = [self._text]
    self.offset_transform = mtransforms.Affine2D()
    self.offset_transform.clear()
    self.offset_transform.translate(0, 0)
    self._baseline_transform = mtransforms.Affine2D()
    self._text.set_transform((self.offset_transform + self._baseline_transform))
    self._multilinebaseline = multilinebaseline
    self._minimumdescent = minimumdescent
