'Provide the operator and some norm-related information.
Parameters
A : linear operator
The operator of interest.
A_1_norm : float, optional
The exact 1-norm of A.
ell : int, optional
A technical parameter controlling norm estimation quality.
scale : int, optional
If specified, return the norms of scale*A instead of A.'

def __init__(self, A, A_1_norm=None, ell=2, scale=1):

    self._A = A
    self._A_1_norm = A_1_norm
    self._ell = ell
    self._d = {}
    self._scale = scale
