code: def testListSpecifyDouble(self):
      self.templatePackUnpack([1.1, 1.6, -7.8], c_double)
  
imports: import unittest
  import numpy
  from pyclustering.core.pyclustering_package import package_builder, package_extractor
  from ctypes import c_ulong, c_size_t, c_double, c_uint, c_float, c_char_p
label_desc: Use image node_id 16 for calling the Test obj's underlying member method code with example usage: obj.testListSpecifyDouble() without return types