code: public JWSHeader setAlgorithm(String algorithm) {
          this.algorithm = algorithm;
          this.put(HeaderConstants.ALGORITHM, algorithm);
          return this;
      }
docs: Sets the algorithm header parameter that identifies the cryptographic algorithm used to
  secure the JWS or {@code null} for none.
  
  <p>
  Overriding is only supported for the purpose of calling the super implementation and changing
  the return type, but nothing else.
  </p>