code: def test_bra():
      b = Bra("0")
  
      assert isinstance(b, Bra)
      assert isinstance(b, BraBase)
      assert isinstance(b, StateBase)
      assert isinstance(b, QExpr)
  
      assert b.label == (Symbol("0"),)
      assert b.hilbert_space == HilbertSpace()
      assert b.is_commutative is False
  
      # Make sure this doesn't get converted to the number pi.
      b = Bra("pi")
      assert b.label == (Symbol("pi"),)
  
      b = Bra(x, y)
      assert b.label == (x, y)
      assert b.hilbert_space == HilbertSpace()
      assert b.is_commutative is False
  
      assert b.dual_class() == Ket
      assert b.dual == Ket(x, y)
      assert b.subs(x, y) == Bra(y, y)
  
      assert Bra() == Bra("psi")
  
imports: from sympy.core.add import Add
  from sympy.core.function import diff
  from sympy.core.mul import Mul
  from sympy.core.numbers import I, Integer, Rational, oo, pi
  from sympy.core.power import Pow
  from sympy.core.singleton import S
  from sympy.core.symbol import Symbol, symbols
  from sympy.core.sympify import sympify
  from sympy.functions.elementary.complexes import conjugate
  from sympy.functions.elementary.miscellaneous import sqrt
  from sympy.functions.elementary.trigonometric import sin
  from sympy.testing.pytest import raises
  from sympy.physics.quantum.dagger import Dagger
  from sympy.physics.quantum.qexpr import QExpr
  from sympy.physics.quantum.state import Ket, Bra, TimeDepKet, TimeDepBra, KetBase, BraBase, StateBase, Wavefunction, OrthogonalKet, OrthogonalBra
  from sympy.physics.quantum.hilbert import HilbertSpace
label_desc: Use image node_id 2 for calling a global function with example usage: test_bra() without return types