def groupmodel(sum=None, ssd=None, jet=None, adaf=None):
    """
Groups the different components of a SED model into one dictionary for convenient
access. The model component SEDs are assumed to have been imported using the
SED class. This method is used in the plot method.

Example:

Imports the model SEDs:
>>> s=SED(file='sum.dat', logfmt=1)
>>> disk=SED(file='disk.dat', logfmt=1)
>>> a=SED(file='adaf.dat', logfmt=1)

Groups them together in a dictionary d:
>>> d=groupmodel(sum=s,ssd=disk,adaf=a)
returning {'sum':s,'ssd':disk,'adaf':a}. 
	"""
    m = {}
    if sum != None:
        m['sum'] = sum
    if ssd != None:
        m['ssd'] = ssd
    if jet != None:
        m['jet'] = jet
    if adaf != None:
        m['adaf'] = adaf
    return m
