class_docstr: This is dummy DataFrame class,
  which imitates pyspark.sql.dataframe.DataFrame class
  for testing purposes.
class_docstr_tok: ["This","is","dummy","DataFrame","class",",","which","imitates","pyspark.sql.dataframe.DataFrame","class","for","testing","purposes","."]
code: def _lazy_evaluation(self):
      if self._data is not None:
          return
      if self._is_map:
          self._data = pd.DataFrame(MAP_DATA, columns=["lat", "lon"])
          return
      if self._is_numpy_arr:
          self._data = pd.DataFrame(
              np.random.randn(self._num_of_rows, 4),
              columns=["A", "B", "C", "D"],
          )
          return
      self._data = pd.DataFrame(
          PERSONAL_DATA,
      )
  
file_path: streamlit/lib/tests/streamlit/pyspark_mocks.py
imports: from __future__ import annotations
  import numpy
  import pandas
  from pyspark.sql.dataframe import DataFrame
  from pyspark.sql.session import SparkSession
  from pyspark.sql.types import FloatType, IntegerType, StringType, StructField, StructType
label_desc: Use image node_id 2 for calling the DataFrame obj's underlying member method code with example usage: obj._lazy_evaluation() without return types