user: Question: Which operator runs the Mamariga Shuttle line?
Columns: ['Line', 'Terminals', 'Status', 'Length', 'Total number of stations', 'Operator']
Types: ['text', 'text', 'text', 'text', 'real', 'text']
Sample row: ['Line 1', 'Etxebarri / Plentzia', 'Complete', '31km', 29.0, 'Metro Bilbao S.A.']
SQL:

assistant: SELECT "Operator" FROM "Table" WHERE "Line" = 'Mamariga Shuttle';