code: def test_invalid_fill_opacity(self):
      with self.assertRaises(traitlets.TraitError):
          Symbol(self.location, fill_opacity=-0.2)
      with self.assertRaises(traitlets.TraitError):
          Symbol(self.location, fill_opacity=1.2)
      with self.assertRaises(traitlets.TraitError):
          Symbol(self.location, fill_opacity="not-a-float")
  
imports: import unittest
  import pytest
  import numpy
  import traitlets
  from ..marker import MarkerOptions, Marker, Markers, Symbol, marker_layer, symbol_layer
label_desc: Use image node_id 4 for calling the SymbolTest obj's underlying member method code with example usage: obj.test_invalid_fill_opacity() without return types