Bigquery parse unexpected token found (= ) in elseif clause

[razvan-am]

Code:

import sqlglot

my_str = """BEGIN

DECLARE MY_VAR INT64 DEFAULT 1;

SET MY_VAR = (SELECT 0);

IF MY_VAR = 1 THEN
    SELECT 'TRUE';
ELSEIF MY_VAR = 0 THEN
    SELECT 'FALSE';
ELSE
    SELECT 'NULL';
END IF;
END
"""

parsed_objects = sqlglot.parse(my_str, dialect='bigquery')

print(parsed_objects)

error:

sqlglot.errors.ParseError: Invalid expression / Unexpected token. Line 9, Col: 15.
  VAR INT64 DEFAULT 1;

SET MY_VAR = (SELECT 0);

IF MY_VAR = 1 THEN
    SELECT 'TRUE';
ELSEIF MY_VAR = 0 THEN
    SELECT 'FALSE';
ELSE
    SELECT 'NULL';
END IF;
END

= is underlined