message: ref to sklearn
diff: @@ -19,7 +19,7 @@ from sklearn.preprocessing import StandardScaler
  class Clamping(BaseEstimator, TransformerMixin):
  """
  - This is a class for clamping a list of values. It is not meant to be called directly on (a list of) persistence diagrams, but it is rather meant to be used as a parameter for the DiagramScaler class. A typical use would be for instance if you want to clamp abscissae or ordinates (or both) of persistence diagrams within a pre-defined interval.
  + This is a class for clamping a list of values. It is not meant to be called directly on (a list of) persistence diagrams, but it is rather meant to be used as a parameter for the DiagramScaler class. As such it has the same methods and purpose than common scalers from sklearn.preprocessing such as MinMaxScaler, RobustScaler, StandardScaler, etc. A typical use would be for instance if you want to clamp abscissae or ordinates (or both) of persistence diagrams within a pre-defined interval.
  """
  def __init__(self, minimum=-np.inf, maximum=np.inf):
  """
  