question: gets the value of the extensions property . this accessor method returns a reference to the live list , not a snapshot . therefore any modification you make to the returned list will be present inside the jaxb object . this is why there is not a set method for the extensions property . for example , to add a new item , do as follows : getextensions . add newitem ; objects of the following type s are allowed in the list extension concode_field_sep List<Extension> extensions concode_elem_sep String name concode_elem_sep String description concode_elem_sep String id concode_elem_sep String href concode_elem_sep String label concode_elem_sep QName type concode_elem_sep List<Description> descriptions concode_elem_sep String value concode_elem_sep String version concode_elem_sep String uuid concode_elem_sep Object idref concode_field_sep List<Description> getDescriptions concode_elem_sep void setName concode_elem_sep String getVersion concode_elem_sep String getHref concode_elem_sep String getName concode_elem_sep String getLabel concode_elem_sep void setVersion concode_elem_sep void setHref concode_elem_sep String getId concode_elem_sep void setDescription concode_elem_sep void setType concode_elem_sep void setUuid concode_elem_sep String getDescription concode_elem_sep String getValue concode_elem_sep void setIdref concode_elem_sep QName getType concode_elem_sep Object getIdref concode_elem_sep void setValue concode_elem_sep String getUuid concode_elem_sep void setId concode_elem_sep void setLabel
target: List < Extension > function ( ) { if ( extensions == null ) { extensions = new ArrayList < Extension > ( ) ; } return this . extensions ; }