'All dimensions are fraction of the figure width or height.
All values default to their rc params
The following attributes are available
left  : 0.125
The left side of the subplots of the figure
right : 0.9
The right side of the subplots of the figure
bottom : 0.1
The bottom of the subplots of the figure
top : 0.9
The top of the subplots of the figure
wspace : 0.2
The amount of width reserved for blank space between subplots,
expressed as a fraction of the average axis width
hspace : 0.2
The amount of height reserved for white space between subplots,
expressed as a fraction of the average axis height'

def __init__(self, left=None, bottom=None, right=None, top=None, wspace=None, hspace=None):

    self.validate = True
    self.update(left, bottom, right, top, wspace, hspace)
