Accessing a test dataset:

    >>> from dap.client import open
    >>> dataset = open('http://server.pydap.org/server.ini/test/sst.mean.nc')
    >>> print dataset.keys()
    ['sst', 'time', 'lat', 'lon']
    >>> sst = dataset['sst']
    >>> print sst.shape
    (173, 90, 180)
    >>> print sst.dimensions
    ('time', 'lat', 'lon')
    >>> sstdata = sst[0,0,:10]  # Here data is downloaded on-the-fly
    >>> print sstdata
    [ [  [ -9.96920997e+36  -9.96920997e+36  -9.96920997e+36  -9.96920997e+36
             -9.96920997e+36  -9.96920997e+36  -9.96920997e+36  -9.96920997e+36
             -9.96920997e+36  -9.96920997e+36]]]
