message: Move documentation string to class
diff: @@ -357,6 +357,16 @@ class BettiCurve2(BaseEstimator, TransformerMixin):
  """
  A more flexible replacement for the BettiCurve class.
  + Parameters
  + ----------
  + grid: 1d array or None, default=None
  + Filtration grid points at which to compute the Betti curves. Must be strictly ordered. Infinites are OK. If None (default), a grid will be computed that captures all the filtration value changes.
  +
  + Attributes
  + ----------
  + grid_: 1d array
  + Contains the compute grid after fit or fit_transform.
  +
  Examples
  --------
  If pd is a persistence diagram and xs is a grid such that xs[0] >= pd.min(), then the result of
  @@ -372,20 +382,6 @@ class BettiCurve2(BaseEstimator, TransformerMixin):
  """
  def __init__(self, grid = None):
  - """
  - Constructor for the BettiCurve class.
  -
  - Parameters
  - ----------
  - grid: 1d array or None, default=None
  - Filtration grid points at which to compute the Betti curves. Must be strictly ordered. Infinites are OK. If None (default), a grid will be computed that captures all the filtration value changes.
  -
  - Attributes
  - ----------
  - grid_: 1d array
  - Contains the compute grid after fit or fit_transform.
  - """
  -
  self.grid_ = np.array(grid)
  