code: @Override
      public String getContentType() {
          String type = this.response.getHeader("Content-Type");
          if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled()) {
              Tr.debug(tc, "getContentType: " + type);
          }
          return type;
      }
docs: /*
  @see javax.servlet.ServletResponse#getContentType()