code: def test_psi_get_salt(self):
      init_fl_context(1, self.target)
      psi = PSI()
      salt = psi.get_salt()
      assert isinstance(salt, str)
  
file_path: BigDL/python/ppml/test/bigdl/ppml/fl/psi/test_psi.py
imports: import unittest
  from bigdl.ppml.fl.psi.psi_client import PSI
  from bigdl.ppml.fl.nn.fl_server import FLServer
  from bigdl.ppml.fl.nn.fl_context import init_fl_context
  from bigdl.ppml.fl.utils import FLTest
label_desc: Use image node_id 3 for calling the TestPSI obj's underlying member method code with example usage: obj.test_psi_get_salt() without return types