code: public EntityBuilder setHref(String href) {
      	if(StringUtils.isBlank(href)) {
      		throw new IllegalArgumentException("href cannot be null or empty.");
      	}
          addStep("setHref", new Object[] { href });
          isEmbedded = true;
          return this;
      }
docs: Set the href of the entity to be built. This method can be called many times
  but only the value of the last call is used in the built entity. This is a required property if this entity is an embedded link, as specified
  by the Siren specification. If set then this entity will be considered an embedded link.
  @param href cannot be <code>null</code> or empty.
  @return <code>this</code> builder, never <code>null</code>.