code: def set(self):
      k = self.scale_matrix.shape[0]
      return MatrixSet(k, k, S.Reals)
  
imports: from math import prod
  from sympy.core.basic import Basic
  from sympy.core.numbers import pi
  from sympy.core.singleton import S
  from sympy.functions.elementary.exponential import exp
  from sympy.functions.special.gamma_functions import multigamma
  from sympy.core.sympify import sympify, _sympify
  from sympy.matrices import ImmutableMatrix, Inverse, Trace, Determinant, MatrixSymbol, MatrixBase, Transpose, MatrixSet, matrix2numpy
  from sympy.stats.rv import _value_check, RandomMatrixSymbol, NamedArgsMixin, PSpace, _symbol_converter, MatrixDomain, Distribution
  from sympy.external import import_module
label_desc: Use image node_id 2 for calling the MatrixGammaDistribution obj's underlying member method code with example usage: obj.set() and returns: MatrixSet