code: public void setDirectShadowBuffer(ByteBuffer buffer) {
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled()) {
              Tr.entry(tc, "setDirectShadowBuffer");
          }
  
          if (!this.trusted)
              checkValidity();
  
          this.oWsBBDirect = buffer;
  
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled()) {
              Tr.exit(tc, "setDirectShadowBuffer");
          }
      }
docs: Set the direct bytebuffer that backs an indirect heap buffer to
  the input buffer.
  
  @param buffer