user: Question: Who directed the episode with 6.37 million viewers?
Columns: ['Episode #', 'Title', 'Directed by', 'Written by', 'Originalairdate', 'Viewers (millions)']
Types: ['real', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, '"Second Life"', 'Brendan Maher', 'Ed Whitmore', '5 July 2010', '6.37']
SQL:

assistant: SELECT "Directed by" FROM "Table" WHERE "Viewers (millions)" = '6.37';