code: def _is_sparse(cls, x1, x2):
      if hasattr(x1, "issparse") and x1.issparse():
          # if x1 is sparse, will be sparse always
          return True
      elif np.isscalar(x1) and x1 == 0:
          # x1 == 0, return sparse if x2 is
          return x2.issparse() if hasattr(x2, "issparse") else False
      return False
  
file_path: mars/mars/tensor/arithmetic/arctan2.py
imports: import numpy
  from ...None import opcodes
  from ..utils import infer_dtype
  from .core import TensorBinOp
  from .utils import arithmetic_operand
label_desc: Use image node_id 1 for calling the TensorArctan2 obj's underlying member method code with example usage: obj._is_sparse(cls, x1, x2) and returns: False, True, unknown