code: def test_FracField___init__():
      F1 = FracField("x,y", ZZ, lex)
      F2 = FracField("x,y", ZZ, lex)
      F3 = FracField("x,y,z", ZZ, lex)
  
      assert F1.x == F1.gens[0]
      assert F1.y == F1.gens[1]
      assert F1.x == F2.x
      assert F1.y == F2.y
      assert F1.x != F3.x
      assert F1.y != F3.y
  
imports: from sympy.polys.fields import field, sfield, FracField, FracElement
  from sympy.polys.rings import ring
  from sympy.polys.domains import ZZ, QQ
  from sympy.polys.orderings import lex
  from sympy.testing.pytest import raises, XFAIL
  from sympy.core import symbols, E
  from sympy.core.numbers import Rational
  from sympy.functions.elementary.exponential import exp, log
  from sympy.functions.elementary.miscellaneous import sqrt
label_desc: Use image node_id 1 for calling a global function with example usage: test_FracField___init__() without return types