Least imported packages in the Go stdlib

SELECT import, SUM(copies) AS COUNT FROM (
  SELECT import, copies FROM
  (
    SELECT REGEXP_EXTRACT(content, r'import "([^"]*)"') AS import, copies
    FROM [campoy-github:go_files.contents]
    WHERE REGEXP_MATCH(content, r'import ".*"')
  ),(
    SELECT REGEXP_EXTRACT(import, r'.*"([^"]*)"') AS import, copies FROM FLATTEN(
      SELECT SPLIT(REGEXP_EXTRACT(content, r'(?s)import \(([^)]*)\)'), '\n') AS import, copies
      FROM [campoy-github:go_files.contents]
      WHERE REGEXP_MATCH(content, r'import \(')
    , import)
  )
)
WHERE import IN (SELECT * FROM [campoy-github:go_files.stdlib])
GROUP BY import
ORDER BY COUNT ASC
LIMIT 10