code: def test_FreeGroup__init__():
      x, y, z = map(Symbol, "xyz")
  
      assert len(FreeGroup("x, y, z").generators) == 3
      assert len(FreeGroup(x).generators) == 1
      assert len(FreeGroup(("x", "y", "z"))) == 3
      assert len(FreeGroup((x, y, z)).generators) == 3
  
imports: from sympy.combinatorics.free_groups import free_group, FreeGroup
  from sympy.core import Symbol
  from sympy.testing.pytest import raises
  from sympy.core.numbers import oo
label_desc: Use image node_id 1 for calling a global function with example usage: test_FreeGroup__init__() without return types