Time to time met with NPE

[gonchik]

org.postgresql.util.PSQLException: This connection has been closed.
	at org.postgresql.jdbc.PgConnection.checkClosed(PgConnection.java:782)
	at org.postgresql.jdbc.PgConnection.getAutoCommit(PgConnection.java:742)
	at org.postgresql.jdbc.PgStatement.executeInternal(PgStatement.java:410)
	at org.postgresql.jdbc.PgStatement.execute(PgStatement.java:370)
	at org.postgresql.jdbc.PgPreparedStatement.executeWithFlags(PgPreparedStatement.java:149)
	at org.postgresql.jdbc.PgPreparedStatement.executeQuery(PgPreparedStatement.java:108)
	at com.atlassian.util.benchmark.JIRASQLPerformance.lambda$getTests$0(JIRASQLPerformance.java:153)
	at com.atlassian.util.benchmark.TimedTestRunner.run(TimedTestRunner.java:21)
	at com.atlassian.util.benchmark.Benchmark.runTests(Benchmark.java:58)
	at com.atlassian.util.benchmark.Benchmark.run(Benchmark.java:71)
	at com.atlassian.util.benchmark.JIRASQLPerformance.call(JIRASQLPerformance.java:85)
	at com.atlassian.util.benchmark.JIRASQLPerformance.main(JIRASQLPerformance.java:59)
java.lang.NullPointerException