[YARN-9140] Code cleanup in ResourcePluginManager.initialize and in TestResourcePluginManager

• Type: Improvement
• Status: Resolved
• Priority: Trivial
• Resolution: Fixed
• Fix Version/s: 3.3.0, 3.2.1, 3.1.3
• Hadoop Flags: Reviewed
• Assignee: Peter Bacsko
• Reporter: Szilard Nemeth
• Created: 16/Dec/18 14:22
• Updated: 14/Aug/19 17:05
• Resolved: 14/Aug/19 17:05

Description

Some code cleanup is needed in ResourcePluginManager#initialize: 

• There's a big code block that initializes resource plugins, this should be extracted to a separate method.
• Exception handling could be simplified.

TestResourcePluginManager minor cleanup: 

• Not thrown exceptions could be deleted from method signatures
• verify(obj, times(1)).<method>() calls: times(1) parameter could be deleted as it is the default if verify(obj) is invoked without the times parameter.
• Some code exceeds the 80 character column limit.