question: gets the value of the refnum property . concode_field_sep XMLGregorianCalendar creditDate concode_elem_sep Double total concode_elem_sep Double amount concode_elem_sep String refNum concode_elem_sep Boolean apply concode_elem_sep Double due concode_elem_sep Long line concode_elem_sep String appliedTo concode_elem_sep Long doc concode_elem_sep String currency concode_elem_sep String type concode_field_sep void setTotal concode_elem_sep String getCurrency concode_elem_sep void setRefNum concode_elem_sep Long getLine concode_elem_sep Long getDoc concode_elem_sep XMLGregorianCalendar getCreditDate concode_elem_sep void setType concode_elem_sep void setCurrency concode_elem_sep Boolean isApply concode_elem_sep void setDue concode_elem_sep void setCreditDate concode_elem_sep void setDoc concode_elem_sep String getType concode_elem_sep Double getDue concode_elem_sep String getAppliedTo concode_elem_sep void setAppliedTo concode_elem_sep void setLine concode_elem_sep Double getTotal concode_elem_sep void setApply concode_elem_sep void setAmount concode_elem_sep Double getAmount
target: String function ( ) { return refNum ; }