public static Header valueExists(final String value)
   {
      return new Header("{" + Header.class.getName() + "_name}", value) {
         @Override
         public String toString()
         {
            return "Header.valueExists(\"" + value + "\")";
         }
      };
   }
public static Header valueExists(final String value)
   {
      return new Header("{" + Header.class.getName() + "_name}", value) {
         @Override
         public String toString()
         {
            return "Header.valueExists(\"" + value + "\")";
         }
      };
   }
public static Header valueExists ( final String value ) { return new Header ( "{" + Header . class . getName ( ) + "_name}" , value ) { @ Override public String toString ( ) { return "Header.valueExists(\"" + value + "\")" ; } } ; }
Create a {@link Header} condition that matches only against the existence of a header with value matching the
given pattern. The header name is ignored.
<p>
The given value pattern may be parameterized:
<p>
<code>
Header.valueExists("application/xml")<br>
Header.valueExists("application/{type}")<br>
Header.valueExists("{anything}")<br>
...
</code>
<p>

@see {@link ConfigurationRuleParameterBuilder#where(String) {@link HttpServletRequest#getHeader(String)}

@param value {@link ParameterizedPattern} matching the header value.
Create a { @link Header } condition that matches only against the existence of a header with value matching the given pattern . The header name is ignored . <p > The given value pattern may be parameterized : <p > <code > Header . valueExists ( application / xml ) <br > Header . valueExists ( application / { type } ) <br > Header . valueExists ( { anything } ) <br > ... < / code > <p >