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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _create_function(name, doc=""):
 """ Create a function for aggregator by name"""

    def _(col):
        spark_ctx = SparkContext._active_spark_context
        java_ctx = (getattr(spark_ctx._jvm.com.sparklingpandas.functions,
                            name)
                    (col._java_ctx if isinstance(col, Column) else col))
        return Column(java_ctx)
    _.__name__ = name
    _.__doc__ = doc
    return _