question: this method was generated by mybatis generator . this method sets the value of the database column history_group . userid concode_field_sep Date lastvisittime concode_elem_sep Integer groupid concode_elem_sep String title concode_elem_sep String userid concode_field_sep void setGroupid concode_elem_sep String getTitle concode_elem_sep int hashCode concode_elem_sep boolean equals concode_elem_sep void setTitle concode_elem_sep void setLastvisittime concode_elem_sep String toString concode_elem_sep String getUserid concode_elem_sep Integer getGroupid concode_elem_sep Date getLastvisittime
target: void function ( String arg0 ) { this . userid = arg0 == null ? null : arg0 . trim ( ) ; }