code: def test_infobox_default_display(self):
      test_content = "test-content"
      options = self._add_default_options(info_box_content=test_content)
      markers = marker_layer(self.locations, **options)
      for marker in markers.markers:
          assert marker.info_box_content == "test-content"
          assert marker.display_info_box
  
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 8 for calling the MarkerLayer obj's underlying member method code with example usage: obj.test_infobox_default_display() without return types