code: def _make_chart(self, N, size, potentials, force_grad=False):
      chart = []
      for _ in range(N):
          c = torch.zeros(
              *((self.semiring.size(),) + size),
              dtype=potentials.dtype,
              device=potentials.device,
          )
          c[:] = self.semiring.zero.view(
              (self.semiring.size(),) + len(size) * (1,)
          )
          c.requires_grad_(force_grad and not potentials.requires_grad)
          chart.append(c)
      return chart
  
file_path: pytorch-struct/torch_struct/helpers.py
imports: import torch
  import math
  from .semirings import LogSemiring
label_desc: Use image node_id 6 for calling the _Struct obj's underlying member method code with example usage: obj._make_chart(N, size, potentials, force_grad) and returns: chart