Make more objects serializable.

5 jobs for ENCAPSULATE_STATISTICS_FIELDS in 34 minutes and 2 seconds (queued for 5 minutes and 32 seconds)
Status Job ID Name Coverage
  Build
passed #8140
jars-j8

00:00:36

passed #8139
java8

00:14:17

 
  Test
failed #8142
allowed to fail
java10

00:02:18

passed #8143
allowed to fail
java11

00:12:49

failed #8141
java7

00:03:59

 
Name Stage Failure
failed
java10 Test
125940 [ERROR] 
125940 [ERROR] Re-run Maven using the -X switch to enable full debug logging.
125940 [ERROR]
125940 [ERROR] For more information about the errors and possible solutions, please read the following articles:
125940 [ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoFailureException
125941 [ERROR]
125941 [ERROR] After correcting the problems, you can resume the build with the command
125941 [ERROR] mvn <goals> -rf :org.ow2.sat4j.core
ERROR: Job failed: exit code 1
failed
java7 Test
226114 [ERROR] 
226114 [ERROR] Re-run Maven using the -X switch to enable full debug logging.
226114 [ERROR]
226114 [ERROR] For more information about the errors and possible solutions, please read the following articles:
226115 [ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoFailureException
226115 [ERROR]
226115 [ERROR] After correcting the problems, you can resume the build with the command
226115 [ERROR] mvn <goals> -rf :org.ow2.sat4j.core
ERROR: Job failed: exit code 1