class_docstr: Immutable matrix based on RepMatrix
  
  Uses DomainMAtrix as the internal representation.
class_docstr_tok: ["Immutable","matrix","based","on","RepMatrix","Uses","DomainMAtrix","as","the","internal","representation","."]
code: def cols(self):
      return self._cols
  
imports: from mpmath.matrices.matrices import _matrix
  from sympy.core import Basic, Dict, Tuple
  from sympy.core.numbers import Integer
  from sympy.core.cache import cacheit
  from sympy.core.sympify import _sympy_converter, _sympify
  from sympy.matrices.dense import DenseMatrix
  from sympy.matrices.expressions import MatrixExpr
  from sympy.matrices.matrixbase import MatrixBase
  from sympy.matrices.repmatrix import RepMatrix
  from sympy.matrices.sparse import SparseRepMatrix
  from sympy.multipledispatch import dispatch
label_desc: Use image node_id 3 for calling the ImmutableRepMatrix obj's underlying member method code with example usage: obj.cols() and returns: self