ARROW_HEAD
ARROW_HEAD: "arrow_head"
ARROW_LINE
ARROW_LINE: "arrow_line"
CONTAIN_TABLE
CONTAIN_TABLE: "contain_table"
EMPTY_CELL
EMPTY_CELL: "empty_cell"
GRAPH_AXIS
GRAPH_AXIS: "graph_axis_line"
GRAPH_GRID
GRAPH_GRID: "graph_grid"
GRAPH_TICK
GRAPH_TICK: "graph_tick"
GRAPH_TICK_LABEL
GRAPH_TICK_LABEL: "graph_tick_label"
TABLE_CELL
TABLE_CELL: "table_cell"
TABLE_CONTENT
TABLE_CONTENT: "table_content"
TEXTVAR
TEXTVAR: "textvar"