'Draw text on the image.
Parameters
text : string
The text to draw
position : tuple
The (x, y) position of the text
coordinates : string
A string code, which should be either \'data\' for data coordinates,
or \'figure\' for figure (pixel) coordinates.
style : dictionary
a dictionary specifying the appearance of the text.
text_type : string or None
if specified, a type of text such as "xlabel", "ylabel", "title"
mplobj : matplotlib object
the matplotlib plot element which generated this text'

def draw_text(self, text, position, coordinates, style, text_type=None, mplobj=None):

    raise NotImplementedError()
