code: public HttpHeaders add(CharSequence name, Object value) {
          return add(name.toString(), value);
      }
docs: Adds a new header with the specified name and value.
  
  If the specified value is not a {@link String}, it is converted
  into a {@link String} by {@link Object#toString()}, except in the cases
  of {@link Date} and {@link Calendar}, which are formatted to the date
  format defined in <a href="http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.3.1">RFC2616</a>.
  
  @param name The name of the header being added
  @param value The value of the header being added
  
  @return {@code this}