android - What is "all" iterator? -

in android plugin gradle, wanted use method suggests use all iterator :

/**  * returns list of application variants. since collections built after evaluation,  * should used groovy's <code>all</code> iterator process future items.  *  */  public defaultdomainobjectset<applicationvariant> getapplicationvariants() {      return applicationvariantlist  } 

however, didn't manage find info iterator on groovy official documentation. can find more info iterator ? how different each iterator ?

finally found all comes from. method gradle api : https://github.com/gradle/gradle/blob/master/subprojects/core/src/main/groovy/org/gradle/api/internal/defaultdomainobjectcollection.java