Gtk.TreeView.prototype.append_column

function append_column(column:Gtk.TreeViewColumn):Number {
    // Gjs wrapper for gtk_tree_view_append_column()
}

Appends column to the list of columns. If tree_view has "fixed_height" mode enabled, then column must have its "sizing" property set to be GTK_TREE_VIEW_COLUMN_FIXED.

column: The Gtk.TreeViewColumn to add.
Returns: The number of columns in tree_view after appending.