How to use the pgspecial.PGSpecial function in pgspecial

def get_completer(self, settings=None, casing=None):
        metadata = self.metadata
        from pgcli.pgcompleter import PGCompleter
        from pgspecial import PGSpecial

        comp = PGCompleter(
            smart_completion=True, settings=settings, pgspecial=PGSpecial()
        )

        schemata, tables, tbl_cols, views, view_cols = [], [], [], [], []

        for sch, tbls in metadata["tables"].items():
            schemata.append(sch)

            for tbl, cols in tbls.items():
                tables.append((sch, tbl))
                # Let all columns be text columns
                tbl_cols.extend([self._make_col(sch, tbl, col) for col in cols])

        for sch, tbls in metadata.get("views", {}).items():
            for tbl, cols in tbls.items():
                views.append((sch, tbl))
                # Let all columns be text columns

logger.debug('System path: %r', sys.path)

    global PGCli, need_completion_refresh, need_search_path_refresh
    global has_meta_cmd, has_change_path_cmd, has_change_db_cmd, OutputSettings
    from pgcli.main import (PGCli, has_meta_cmd, has_change_path_cmd,
        has_change_db_cmd, OutputSettings)

    global PGExecute
    from pgcli.pgexecute import PGExecute

    global PGCompleter
    from pgcli.pgcompleter import PGCompleter

    global special
    from pgspecial import PGSpecial
    special = PGSpecial()

    global CompletionRefresher
    from pgcli.completion_refresher import CompletionRefresher

    global Document
    from prompt_toolkit.document import Document

    global format_output
    from pgcli.main import format_output

    global psycopg2
    import psycopg2

    global sqlparse
    import sqlparse