code: def conversion_data():
      df = pd.DataFrame(
          [
              {
                  "str_num": "1.5",
                  "str_date": "20200101",
                  "str_date2": "1/1/2020",
                  "str_bool": "True",
                  "int": 1,
                  "int_date": 20200101,
                  "int_s": 1490195805,
                  "float": 1.5,
                  "date": pd.Timestamp("20200101"),
                  "bool": True,
                  "cat_int": "1",
                  "cat_bool": "True",
                  "cat_str": "a",
              }
          ]
      )
      for c in ["cat_int", "cat_bool", "cat_str"]:
          df.loc[:, c] = df[c].astype("category")
      return df
  
file_path: dtale/tests/dtale/column_builders/test_type_conversion.py
imports: import numpy
  import pandas
  import pytest
  from dtale.column_builders import ColumnBuilder
  from tests.dtale.column_builders.test_column_builders import verify_builder
  from tests.dtale import build_data_inst
label_desc: Use image node_id 1 for calling a global function with example usage: conversion_data() and returns: df