code: public final byte[] genExemptionBlob() throws IllegalStateException,
              ExemptionMechanismException {
          if (!initialized) {
              throw new IllegalStateException(
                  "ExemptionMechanism not initialized");
          }
          byte[] blob = exmechSpi.engineGenExemptionBlob();
          done = true;
          return blob;
      }
docs: Generates the exemption mechanism key blob.
  
  @return the new buffer with the result key blob.
  
  @exception IllegalStateException if this exemption mechanism is in
  a wrong state (e.g., has not been initialized).
  @exception ExemptionMechanismException if problem(s) encountered in the
  process of generating.