code: def test_real():
      assert satask(Q.real(x * y), Q.real(x) & Q.real(y)) is True
      assert satask(Q.real(x + y), Q.real(x) & Q.real(y)) is True
      assert (
          satask(Q.real(x * y * z), Q.real(x) & Q.real(y) & Q.real(z))
          is True
      )
      assert satask(Q.real(x * y * z), Q.real(x) & Q.real(y)) is None
      assert (
          satask(
              Q.real(x * y * z), Q.real(x) & Q.real(y) & Q.imaginary(z)
          )
          is False
      )
      assert (
          satask(Q.real(x + y + z), Q.real(x) & Q.real(y) & Q.real(z))
          is True
      )
      assert satask(Q.real(x + y + z), Q.real(x) & Q.real(y)) is None
  
imports: from sympy.assumptions.ask import Q
  from sympy.assumptions.assume import assuming
  from sympy.core.numbers import I, pi
  from sympy.core.relational import Eq, Gt
  from sympy.core.singleton import S
  from sympy.core.symbol import symbols
  from sympy.functions.elementary.complexes import Abs
  from sympy.logic.boolalg import Implies
  from sympy.matrices.expressions.matexpr import MatrixSymbol
  from sympy.assumptions.cnf import CNF, Literal
  from sympy.assumptions.satask import satask, extract_predargs, get_relevant_clsfacts
  from sympy.testing.pytest import raises, XFAIL
label_desc: Use image node_id 14 for calling a global function with example usage: test_real() without return types