An input stream that always returns the same RDD on each timestep.
A Discretized Stream (DStream), the basic abstraction in Spark Streaming, is a continuous sequence of RDDs (of the same type) representing a continuous stream of data (see org.apache.spark.rdd.RDD in the Spark core documentation for more details on RDDs).
This is the abstract base class for all input streams.
Extra functions available on DStream of (key, value) pairs through an implicit conversion.
Abstract class for defining any