code: def exponential_map(term):
      
      if not np.isclose(np.imag(term.coefficient), 0.0):
          raise TypeError("PauliTerm coefficient must be real")
  
      coeff = term.coefficient.real
      term.coefficient = term.coefficient.real
  
      def exp_wrap(param):
          prog = Program()
          if is_identity(term):
              prog.inst(X(0))
              prog.inst(PHASE(-param * coeff, 0))
              prog.inst(X(0))
              prog.inst(PHASE(-param * coeff, 0))
          elif is_zero(term):
              pass
          else:
              prog += _exponentiate_general_case(term, param)
          return prog
  
      return exp_wrap
docs: Returns a function f(alpha) that constructs the Program corresponding to exp(-1j*alpha*term).
  
      :param term: A pauli term to exponentiate
      :returns: A function that takes an angle parameter and returns a program.
      :rtype: Function