class_docstr: A Numba `Type` modeled after the base class `scipy.sparse.compressed._cs_matrix`.
class_docstr_tok: ["A","Numba","`","Type","`","modeled","after","the","base","class","`","scipy.sparse.compressed._cs_matrix","`","."]
code: def key(self):
      return (self.name, self.dtype)
  
imports: import numpy
  import scipy
  import scipy.sparse
  from numba.core import cgutils, types
  from numba.core.imputils import impl_ret_borrowed
  from numba.extending import NativeValue, box, intrinsic, make_attribute_wrapper, models, overload, overload_attribute, overload_method, register_model, typeof_impl, unbox
label_desc: Use image node_id 3 for calling the CSMatrixType obj's underlying member method code with example usage: obj.key() and returns: self,  self