title: Why is there no initiallyDeferred parameter on Liquibase addNotNullConstraint?
body: <p>Any reason why Liquibase's <a href="http://www.liquibase.org/documentation/changes/add_not_null_constraint.html" rel="nofollow noreferrer">addNotNullConstraint</a> doesn't have an attribute <code>initiallyDeferred</code>?</p>
  
  <p><a href="http://www.liquibase.org/documentation/changes/add_foreign_key_constraint.html" rel="nofollow noreferrer">addForeignKeyConstraint</a> and <a href="http://www.liquibase.org/documentation/changes/add_unique_constraint.html" rel="nofollow noreferrer">addUniqueConstraint</a> both have an attribute <code>initiallyDeferred</code>.</p>