code: func (p *Parser) parseShowRetentionPoliciesStatement() (*ShowRetentionPoliciesStatement, error) {
  	stmt := &ShowRetentionPoliciesStatement{}
  
  	// Expect an "ON" keyword.
  	if tok, _, _ := p.ScanIgnoreWhitespace(); tok == ON {
  		// Parse the database.
  		ident, err := p.ParseIdent()
  		if err != nil {
  			return nil, err
  		}
  		stmt.Database = ident
  	} else {
  		p.Unscan()
  	}
  
  	return stmt, nil
  }
docs: // parseShowRetentionPoliciesStatement parses a string and returns a ShowRetentionPoliciesStatement.
  // This function assumes the "SHOW RETENTION POLICIES" tokens have been consumed.