title: Checkstyle Java generics: '?' is not preceded with whitespace
body: <p>I am using plugin  </p>
  
  <pre class="lang-xml prettyprint-override"><code>&lt;artifactId&gt;maven-checkstyle-plugin&lt;/artifactId&gt;
  &lt;version&gt;2.17&lt;/version&gt;
  </code></pre>
  
  <p>It has 6.11.2 checkstyle version. Configuration saying about whitespaces is:</p>
  
  <pre class="lang-xml prettyprint-override"><code>&lt;module name="NoWhitespaceAfter"&gt;
      &lt;property name="severity" value="error" /&gt;
      &lt;property name="tokens" value="ARRAY_INIT,BNOT,DEC,DOT,INC,LNOT" /&gt;
  &lt;/module&gt;
  &lt;module name="NoWhitespaceBefore"&gt;
      &lt;property name="severity" value="error" /&gt;
  &lt;/module&gt;
  &lt;module name="RedundantModifier"&gt;
      &lt;property name="severity" value="error" /&gt;
  &lt;/module&gt;
  &lt;module name="WhitespaceAround"&gt;
      &lt;property name="severity" value="error" /&gt;
      &lt;property name="tokens" value="ASSIGN,BAND,BAND_ASSIGN,BOR,BOR_ASSIGN,BSR,BSR_ASSIGN,BXOR,BXOR_ASSIGN,COLON,DIV,DIV_ASSIGN,DO_WHILE,EQUAL,GE,LAND,LCURLY,LE,LITERAL_ASSERT,LITERAL_CATCH,LITERAL_DO,LITERAL_ELSE,LITERAL_FINALLY,LITERAL_FOR,LITERAL_IF,LITERAL_RETURN,LITERAL_SYNCHRONIZED,LITERAL_TRY,LITERAL_WHILE,LOR,MINUS,MINUS_ASSIGN,MOD,MOD_ASSIGN,NOT_EQUAL,PLUS,PLUS_ASSIGN,RCURLY,SL,SLIST,SL_ASSIGN,SR,SR_ASSIGN,STAR,STAR_ASSIGN,TYPE_EXTENSION_AND" /&gt;
  &lt;/module&gt;
  </code></pre>
  
  <p>I always get this error:  </p>
  
  <pre class="lang-none prettyprint-override"><code>(whitespace) WhitespaceAround: WhitespaceAround: '?' is not preceded with whitespace.  
  (whitespace) WhitespaceAround: WhitespaceAround: '?' is not followed by whitespace.
  Empty blocks may only be represented as {} when not part of a multi-block statement (4.1.3)
  </code></pre>
  
  <p>The code snippets are:</p>
  
  <pre class="lang-java prettyprint-override"><code>Class&lt;?&gt;[] groups() default {};  
  Class&lt;? extends Payload&gt;[] payload() default {};
  </code></pre>
  
  <p>I tried to remove the snippet with whitespaces, but still get the same error.  </p>