EmptyLineSeparator doesn't require exactly one line between members

[mkordas]

According to Google Java Style - Vertical Whitespace there must be only one line between class members. Current check doesn't enforce that, so it's incomplete. Please look at samples:

package com.sample;
import java.util.List; // as expected: 'import' should be separated from previous statement

package com.sample;

import java.util.List; // OK

package com.sample;


import java.util.List; // nothing reported, but violates Vertical Whitespace rules

[romani]

that should be a new option of Check, by default Check should allow multiple empty lines

[romani]

will be in 6.3

[romani]

problem is detected by google style test project - https://travis-ci.org/checkstyle/google-style-config-test/jobs/49054029