user: Question: Who had the high assists when the high rebounds were from Nick Collison (15)?
Columns: ['Game', 'Date', 'Team', 'Score', 'High points', 'High rebounds', 'High assists', 'Location Attendance', 'Record']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [75.0, 'April 2', 'L. A. Clippers', 'L 84–102 (OT)', 'Kevin Durant (30)', 'Nick Collison (17)', 'Luke Ridnour (6)', 'KeyArena 10,392', '17–58']
SQL:

assistant: SELECT "High assists" FROM "Table" WHERE "High rebounds" = 'Nick Collison (15)';