class_docstr: Desc: Data preprocessing,
code: def build_graph_data(self, df_data):
      cols_data = df_data.columns[self.start_col :]
      df_data = df_data[cols_data]
      raw_df_data = self.raw_df_data[cols_data]
      data = df_data.values
      raw_data = raw_df_data.values
  
      data = np.reshape(data, [self.capacity, -1, len(cols_data)])
      raw_data = np.reshape(
          raw_data, [self.capacity, -1, len(cols_data)]
      )
  
      data_x = data[:, :, :]
  
      self.raw_df = []
      for turb_id in range(self.capacity):
          self.raw_df.append(
              pd.DataFrame(data=raw_data[turb_id], columns=cols_data)
          )
      return np.expand_dims(data_x, [0])
  
imports: import os
  import time
  import datetime
  import numpy
  import pandas
  import paddle
  from paddle.io import Dataset
  import pgl
  from pgl.utils.logger import log
label_desc: Use image node_id 5 for calling the TestPGL4WPFDataset obj's underlying member method code with example usage: obj.build_graph_data(df_data) and returns: np