PM-1372 Remove unused imports, sort imports, source code format. Use `from __future__ import unicode_literals` to ensure file is unicode compliant.
PM-1372 Remove unused imports, sort imports, source code format. Use `from __future__ import unicode_literals` to ensure file is unicode compliant.

pegasus-isi/pegasus,pegasus-isi/pegasus,pegasus-isi/pegasus,pegasus-isi/pegasus,pegasus-isi/pegasus,pegasus-isi/pegasus,pegasus-isi/pegasus,pegasus-isi/pegasus,pegasus-isi/pegasus,pegasus-isi/pegasus