<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def fromDataFrameRDD(cls, rdd, sql_ctx):
 """Construct a DataFrame from an RDD of DataFrames. No checking or validation occurs."""

        result = DataFrame(None, sql_ctx)
        return result.from_rdd_of_dataframes(rdd)