code: def test_stroke_color_list_tuples(self):
      c1 = (10, 10, 10, 0.5)
      c2 = (20, 20, 20, 0.5)
      options = self._add_default_options(stroke_color=[c1, c2])
      symbols = symbol_layer(self.locations, **options)
      colors = [symbol.stroke_color for symbol in symbols.markers]
      assert colors == ["rgba(10,10,10,0.5)", "rgba(20,20,20,0.5)"]
  
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 9 for calling the SymbolLayer obj's underlying member method code with example usage: obj.test_stroke_color_list_tuples() without return types