code: def get_data(self):
      return pandas.DataFrame(
          {
              "a": [
                  ["a", "b"],
                  ["a", "b", "c"],
                  ["c", "d"],
                  ["a", "e"],
                  None,
              ],
              "b": [[0, 1, 2], None, [2, 3, 4, 5], [1], [-1, 10]],
              "target": [1, 0, 1, 0, 1],
          }
      )
  
imports: import datetime
  import pandas
  import sqlalchemy
  from lore.encoders import Unique, Pass, Token, Boolean, Enum, Continuous, OneHot, NestedUnique, NestedNorm
  from lore.transformers import DateTime
  import lore.io
  import lore.pipelines.holdout
  import lore.pipelines.iterative
  import lore.pipelines.time_series
label_desc: Use image node_id 1 for calling the MockNestedData obj's underlying member method code with example usage: obj.get_data() and returns: pandas