Clears namespaced objects (highlights, extmarks, virtual text) from a region. Lines are 0-indexed. |api-indexing| To clear the namespace in the entire buffer, specify line_start=0 and line_end=-1. Parameters: ~ {buffer} Buffer handle, or 0 for current buffer {ns_id} Namespace to clear, or -1 to clear all namespaces. {line_start} Start of range of lines to clear {line_end} End of range of lines to clear (exclusive) or -1 to clear to end of buffer.