code: def testDbToAmp(self):
      db = -45.5
      expected_amp = 10 ** (0.5 * db / 10.0)
      self.assertAlmostEqual(expected_amp, db2amp(db), 5e-7)
  
file_path: essentia/test/src/unittests/base/test_utils.py
imports: from essentia_test import *
  import math
  import cmath
  import sys
label_desc: Use image node_id 10 for calling the TestUtils obj's underlying member method code with example usage: obj.testDbToAmp() without return types