for ( String key : versions.keySet() )
{
if ( versions.get( key ) == null && managedVersions.get( key ) == null )
{
InputLocation location = plugins.get( key ).getLocation( "" );
problems.add( new ModelProblemCollectorRequest( Severity.WARNING, Version.V20 )
.setMessage( "'build.plugins.plugin.version' for " + key + " is missing." )
.setLocation( location ) );
}
}