code: def basic_spec():
      return {
          "data": {"url": "data.csv"},
          "mark": {"type": "line"},
          "encoding": {
              "color": {"type": "nominal", "field": "color"},
              "x": {"type": "quantitative", "field": "xval"},
              "y": {"type": "ordinal", "field": "yval"},
          },
      }
  
file_path: altair/tests/vegalite/test_common.py
imports: import pytest
  import pandas
  from altair.vegalite import v5
label_desc: Use image node_id 1 for calling a global function with example usage: basic_spec() and returns: dict