ram : bool, default=True
    Whether the gram matrix must be copied by the algorithm. A false
    value is only helpful if it is already Fortran-ordered, otherwise a
    copy is made anyway.

copy_Xy : bool, default=True
    Whether the covariance vector Xy must be copied by the algorithm.
    If False, it may be overwritten.

return_path : bool, default=False
    Whether to return every value of the nonzero coefficients along the
    forward path. Useful for cross-validation.

Returns
-------
gamma : ndarray of shape (n_nonzero_coefs,)
    Non-zero elements of the solution.

idx : ndarray of shape (n_nonzero_coefs,)
    Indices of the positions of the elements in gamma within the solution
    vector.

coefs : ndarray of shape (n_features, n_nonzero_coefs)
    The first k values of column k correspond to the coefficient value
    for the active features at that step. The lower left triangle contains
    garbage. Only returned if ``return_path=True``.

n_active : int
    Number of active features at convergence.
r