'The number of rows and number of columns of the grid need to
be set. An instance of SubplotSpec is also needed to be set
from which the layout parameters will be inherited. The wspace
and hspace of the layout can be optionally specified or the
default values (from the figure or rcParams) will be used.'

def __init__(self, nrows, ncols, subplot_spec, wspace=None, hspace=None, height_ratios=None, width_ratios=None):

    self._wspace = wspace
    self._hspace = hspace
    self._subplot_spec = subplot_spec
    GridSpecBase.__init__(self, nrows, ncols, width_ratios=width_ratios, height_ratios=height_ratios)
