remove pointless comment

Change-Id: I93d3ff3f17368b22f524f2f8670f950cdbcecc98
clean code

Change-Id: I3fa4706116870364d0753a61555eab62774c2d57
Add type hint

Change-Id: If05d1fdd26ec21dd3fd73bdf3ec0e9022d924064
clean

Change-Id: If1bfb2fad30215b391361abfaf38b5898a93d5f5
improve names

Change-Id: I1914bd674c2360a79712bbd032cc82687cd0702d
rem dead code

Change-Id: I829fed319771328f9a7556336faa2b7f6b1dc0ad