+ /**
+ * Whether this attribute has to be set at instantiation of the flow and
+ * cannot be modified afterwards. If the attribute is not immutable (that
+ * is, this method returns false), it can be set at execution time.
+ */
+ public Boolean getIsImmutable();
+
+ /**
+ * Whether this attribute must be explicitly set and cannot be modified.
+ * This attribute is then basically a constant within a given application
+ * context. {@link #getValue()} cannot return null if the attribute is a
+ * constant.
+ */
+ public Boolean getIsConstant();
+
+ /** Whether this attribute will be hidden to end users. */
+ public Boolean getIsHidden();
+
+ /**
+ * The default value for this attribute. Can be null, except if
+ * {@link #getIsFrozen()} is <code>true</code>, in which case it represents
+ * the constant value of this attribute.
+ */