question: gets the value of the columns 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 columns property . for example , to add a new item , do as follows : getcolumns . add newitem ; objects of the following type s are allowed in the list column concode_field_sep ReportQueryAdUnitView adUnitView concode_elem_sep List<Long> customFieldIds concode_elem_sep List<DimensionFilter> dimensionFilters concode_elem_sep Date endDate concode_elem_sep List<Column> columns concode_elem_sep List<Long> contentMetadataKeyHierarchyCustomTargetingKeyIds concode_elem_sep DateRangeType dateRangeType concode_elem_sep List<DimensionAttribute> dimensionAttributes concode_elem_sep Statement statement concode_elem_sep String timeZone concode_elem_sep Date startDate concode_elem_sep List<Dimension> dimensions concode_field_sep Date getStartDate concode_elem_sep void setStartDate concode_elem_sep List<DimensionAttribute> getDimensionAttributes concode_elem_sep String getTimeZone concode_elem_sep List<Long> getCustomFieldIds concode_elem_sep Date getEndDate concode_elem_sep void setEndDate concode_elem_sep DateRangeType getDateRangeType concode_elem_sep List<Dimension> getDimensions concode_elem_sep List<DimensionFilter> getDimensionFilters concode_elem_sep void setAdUnitView concode_elem_sep void setDateRangeType concode_elem_sep void setStatement concode_elem_sep List<Long> getContentMetadataKeyHierarchyCustomTargetingKeyIds concode_elem_sep void setTimeZone concode_elem_sep ReportQueryAdUnitView getAdUnitView concode_elem_sep Statement getStatement
target: List < Column > function ( ) { if ( columns == null ) { columns = new ArrayList < Column > ( ) ; } return this . columns ; }