class_docstr: Utility class for performing a group by operation over a lazy DataFrame.
  
  Generated by calling `df.lazy().group_by(...)`.
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docstr: Apply a custom/user-defined function (UDF) over the groups as a new DataFrame.
  
  .. deprecated:: 0.19.0
      This method has been renamed to :func:`LazyGroupBy.map_groups`.
  
  Parameters
  ----------
  function
      Function to apply over each group of the `LazyFrame`.
  schema
      Schema of the output function. This has to be known statically. If the
      given schema is incorrect, this is a bug in the caller's query and may
      lead to errors. If set to None, polars assumes the schema is unchanged.
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code: def apply(
      self,
      function: Callable[[DataFrame], DataFrame],
      schema: SchemaDict | None,
  ) -> LazyFrame:
      """
      Apply a custom/user-defined function (UDF) over the groups as a new DataFrame.
  
      .. deprecated:: 0.19.0
          This method has been renamed to :func:`LazyGroupBy.map_groups`.
  
      Parameters
      ----------
      function
          Function to apply over each group of the `LazyFrame`.
      schema
          Schema of the output function. This has to be known statically. If the
          given schema is incorrect, this is a bug in the caller's query and may
          lead to errors. If set to None, polars assumes the schema is unchanged.
  
      """
      return self.map_groups(function, schema)
  
imports: from __future__ import annotations
  from typing import TYPE_CHECKING, Callable, Iterable
  from polars import functions
  from polars.utils._parse_expr_input import parse_as_list_of_expressions
  from polars.utils._wrap import wrap_ldf
  from polars.utils.deprecation import deprecate_renamed_function
label_desc: Use image node_id 17 for calling the LazyGroupBy obj's underlying member method code with example usage: obj.apply(function, schema) and returns: self