Who directed the episode entitled 'Shotgun'?
CREATE TABLE table_3157 (
    "No. in series" real,
    "No. in season" real,
    "Title" text,
    "Directed by" text,
    "Written by" text,
    "Original air date" text,
    "U.S. viewers (millions)" text
)
SELECT "Directed by" FROM table_3157 WHERE "Title" = 'Shotgun'
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: Who directed the episode entitled 'Shotgun'? ### Input: CREATE TABLE table_3157 (
    "No. in series" real,
    "No. in season" real,
    "Title" text,
    "Directed by" text,
    "Written by" text,
    "Original air date" text,
    "U.S. viewers (millions)" text
) ### Response: SELECT "Directed by" FROM table_3157 WHERE "Title" = 'Shotgun'