code: def to_camel_case(prefix: str, varname: str) -> str:
      parts = varname.split("_")
      first = (
          parts[0][0:1].upper() + parts[0][1:]
          if prefix != ""
          else parts[0]
      )
      residual = [pp[0:1].upper() + pp[1:] for pp in parts[1:]]
      return prefix + "".join([first] + residual)
  
imports: from typing import Any, List, Union
  from pyspark.ml.param.shared import HasInputCol, HasOutputCol, Param
  from pyspark.sql import DataFrame, SparkSession, functions, types
  from pyspark.sql.window import Window
label_desc: Use image node_id 1 for calling a global function with example usage: to_camel_case(prefix, varname) and returns: unknown