fieldName = fieldName.substring(idx + 1);
                    key = fieldName;
                }

                if (fieldName.endsWith("]")) {
                    key = fieldName.substring(fieldName.lastIndexOf('[') + 1, fieldName.length() - 1);
                    try {
                        key = Integer.valueOf(key.toString());
                    } catch (NumberFormatException e) {

            List<BuilderProblem> problems, String fieldName, String string, String sourceHint) {
        if (!validateNotNull(problems, fieldName, string, sourceHint)) {
            return false;
        }

        if (!string.isEmpty()) {
            return true;
        }

        addViolation(problems, BuilderProblem.Severity.ERROR, fieldName, sourceHint, "is missing");

        return false;
    }

                    key = fieldName;
                }

                if (fieldName.endsWith("]")) {
                    key = fieldName.substring(fieldName.lastIndexOf('[') + 1, fieldName.length() - 1);
                    try {
                        key = Integer.valueOf(key.toString());
                    } catch (NumberFormatException e) {

         *
         * @param source    The source value
         * @param fieldName A description of the field being interpolated. The implementation may use this to
         *                  log stuff.
         * @return The interpolated value.
         */
        String transform(String source, String fieldName);
    }

         * @param source The source value
         * @param fieldName A description of the field being interpolated. The implementation may use this to
         *                           log stuff.
         * @return The interpolated value.
         */
        String transform(String source, String fieldName);
    }

          <name>roleHint</name>
          <version>1.0.0+</version>
          <type>String</type>
          <description></description>
        </field>
        <field xml.tagName="field-name">
          <name>fieldName</name>
          <required>true</required>
          <version>1.0.0+</version>
          <type>String</type>
          <description>The field name which has this requirement.</description>
        </field>