question: gets the value of the trendline 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 trendline property . for example , to add a new item , do as follows : gettrendline . add newitem ; objects of the following type s are allowed in the list cttrendline concode_field_sep CTNumDataSource val concode_elem_sep CTSerTx tx concode_elem_sep CTDLbls dLbls concode_elem_sep CTShape shape concode_elem_sep CTErrBars errBars concode_elem_sep CTExtensionList extLst concode_elem_sep List<CTDPt> dPt concode_elem_sep CTShapeProperties spPr concode_elem_sep CTBoolean invertIfNegative concode_elem_sep List<CTTrendline> trendline concode_elem_sep CTAxDataSource cat concode_elem_sep CTPictureOptions pictureOptions concode_elem_sep CTUnsignedInt idx concode_elem_sep CTUnsignedInt order concode_field_sep void setErrBars concode_elem_sep void setTx concode_elem_sep void setPictureOptions concode_elem_sep CTDLbls getDLbls concode_elem_sep CTShape getShape concode_elem_sep CTBoolean getInvertIfNegative concode_elem_sep CTUnsignedInt getIdx concode_elem_sep void setSpPr concode_elem_sep void setCat concode_elem_sep void setExtLst concode_elem_sep List<CTDPt> getDPt concode_elem_sep void setVal concode_elem_sep CTErrBars getErrBars concode_elem_sep CTSerTx getTx concode_elem_sep CTNumDataSource getVal concode_elem_sep CTExtensionList getExtLst concode_elem_sep CTPictureOptions getPictureOptions concode_elem_sep CTAxDataSource getCat concode_elem_sep void setShape concode_elem_sep void setDLbls concode_elem_sep CTShapeProperties getSpPr concode_elem_sep void setOrder concode_elem_sep CTUnsignedInt getOrder concode_elem_sep void setIdx concode_elem_sep void setInvertIfNegative
target: List < CTTrendline > function ( ) { if ( trendline == null ) { trendline = new ArrayList < CTTrendline > ( ) ; } return this . trendline ; }