code: @Override
      public void setDateHeader(String hdr, long value) {
          if (-1L == value) {
              if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled()) {
                  Tr.debug(tc, "setDateHeader(" + hdr + ", -1), removing header");
              }
              this.response.removeHeader(hdr);
          } else {
              this.response.setHeader(hdr, connection.getDateFormatter().getRFC1123Time(new Date(value)));
          }
      }
docs: /*
  @see javax.servlet.http.HttpServletResponse#setDateHeader(java.lang.String, long)