Make more objects serializable.

5 jobs for ENCAPSULATE_STATISTICS_FIELDS in 43 minutes and 6 seconds (queued for 5 minutes and 12 seconds)
Status Job ID Name Coverage
  Build
passed #8151
jars-j8

00:00:35

passed #8150
java8

00:13:56

 
  Test
failed #8153
allowed to fail
java10

00:02:20

passed #8154
allowed to fail
java11

00:12:40

passed #8152
java7

00:13:33

 
Name Stage Failure
failed
java10 Test
126085 [ERROR] 
126086 [ERROR] Re-run Maven using the -X switch to enable full debug logging.
126087 [ERROR]
126087 [ERROR] For more information about the errors and possible solutions, please read the following articles:
126089 [ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoFailureException
126090 [ERROR]
126091 [ERROR] After correcting the problems, you can resume the build with the command
126094 [ERROR] mvn <goals> -rf :org.ow2.sat4j.core
ERROR: Job failed: exit code 1