code: public MCMutualAuthConfig setProperty(String name, String value) {
          properties.put(name, value);
          return this;
      }
docs: Sets a property.
  
  @param name  the name of the property to set
  @param value the value of the property to set
  @return the updated MCMutualAuthConfig
  @throws NullPointerException if name or value is {@code null}