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Article History

Received: 20 June 2018

Accepted: 24 October 2018

First Online: 8 November 2018

Ethics approval and consent to participate

: The study did not include any human subjects or human materials, and ethical approval of the study was thus not required based on guidance from the institutional review board of An-Najah National University.

: Not applicable.

: The author declares that he has no competing interests.

: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.