private String makeConverterKey(Class<?> fromClass, String syntax, Class<?> toClass) {
        StringBuilder key = new StringBuilder();
        if (syntax==null) {
            syntax="";
        }
        key.append(fromClass.getName()).append(KEY_SEP).append(syntax).append(KEY_SEP).append(toClass.getName());
        return key.toString();
    }
private String makeConverterKey ( Class < ? > fromClass , String syntax , Class < ? > toClass ) { StringBuilder key = new StringBuilder ( ) ; if ( syntax == null ) { syntax = "" ; } key . append ( fromClass . getName ( ) ) . append ( KEY_SEP ) . append ( syntax ) . append ( KEY_SEP ) . append ( toClass . getName ( ) ) ; return key . toString ( ) ; }
Make a key into the converters map - the keys is formed from the <code>fromClass</code>, syntax and <code>toClass</code>

@param fromClass The class to convert from.
@param syntax The LDAP syntax.
@param toClass The class to convert to.
@return key