code: public static Character convertChar(Object target) {
          if (target instanceof JsonNode) {
              return convertChar((JsonNode) target);
          }
          return target instanceof Character ? (Character) target
                  : target instanceof Number ? (char) ((Number) target).intValue()
                          : target instanceof String
                                  ? target.toString().length() > 0 ? target.toString().charAt(0) : 0
                                  : 0;
      }
docs: Convert a target object to {@link Character}.
  
  <p>
  Nullable: this method does not return {@code null}. If {@code target} can not be converted to
  {@Link Character}, character {@code #0} is returned.
  </p>
  
  @param target
  @return