NullPointerException in using RecyclerView

[rajendrachauhan]

java.lang.NullPointerException:
at com.twotoasters.jazzylistview.JazzyHelper.doJazzinessImpl (JazzyHelper.java:197)
at com.twotoasters.jazzylistview.JazzyHelper.doJazziness (JazzyHelper.java:189)
at com.twotoasters.jazzylistview.JazzyHelper.onScrolled (JazzyHelper.java:122)
at com.twotoasters.jazzylistview.recyclerview.JazzyRecyclerViewScrollListener.onScrolled (JazzyRecyclerViewScrollListener.java:24)