code: def runtest_autowrap_matrix_matrix(language, backend):
      has_module("numpy")
      expr = Eq(C[i, j], A[i, k] * B[k, j])
      matmat = autowrap(expr, language, backend)
  
      # compare with numpy's dot product
      M1 = numpy.random.rand(10, 20)
      M2 = numpy.random.rand(20, 15)
      M3 = numpy.dot(M1, M2)
      assert numpy.sum(numpy.abs(M3 - matmat(M1, M2))) < 1e-13
  
imports: import sympy
  import tempfile
  import os
  from sympy.core.mod import Mod
  from sympy.core.relational import Eq
  from sympy.core.symbol import symbols
  from sympy.external import import_module
  from sympy.tensor import IndexedBase, Idx
  from sympy.utilities.autowrap import autowrap, ufuncify, CodeWrapError
  from sympy.testing.pytest import skip
label_desc: Use image node_id 5 for calling a global function with example usage: runtest_autowrap_matrix_matrix(language, backend) without return types