code: def project(cls, X, alpha, k):
      return sparsemax(X, dim=-1, k=k)
  
imports: import torch
  import torch.nn
  from torch.autograd import Function
  from ludwig.constants import IGNORE_INDEX_TOKEN_ID
  from ludwig.utils.entmax.activations import entmax15, sparsemax
  from ludwig.utils.entmax.root_finding import entmax_bisect, sparsemax_bisect
label_desc: Use image node_id 1 for calling the SparsemaxLossFunction obj's underlying member method code with example usage: obj.project(cls, X, alpha, k) and returns: sparsemax