public Element getIn() {
            return in;
        }
Insert a pipeline element that will notify the controller when the end of
a record is detected. For XML this is whenever endDocument() is called.
For text it it when a new line character is reached.

@param elementType The type of the element that we might be inserting a record
                   detector before or after.
@param fragment    The current pipeline fragment we are modifying.
@param input       True if we are modifying the input element of the fragment,
                   false if we are modifying the output.
@param controller  The stepping controller.
@return A modified pipeline fragment if a record detector was added or
the original if it remains unchanged.
stroom-pipeline/src/main/java/stroom/pipeline/factory/PipelineFactory.java