prompt: You will be provided with a partial code base and an issue statement explaining a problem to resolve.
  <issue>
  BBAN for en_GB too short
  * Faker version: v2.0.3
  * OS: linux
  
  Numeric part of the en_GB BBAN needs to be 14 digits long, it currently only returns 13, failing further validation.
  
  ### Steps to reproduce
  
  Invoke `fake.iban()` or `fake.bban()` with the en_GB locale, an IBAN or BBAN with 1 digit missing is returned.
  
  ### Expected behavior
  
  GB ibans should be 22 chars long: https://www.xe.com/ibancalculator/sample/?ibancountry=united kingdom
  
  
  
  </issue>
  <code>
  [start of faker/providers/bank/en_GB/__init__.py]
  1 from .. import Provider as BankProvider
  2 
  3 
  4 class Provider(BankProvider):
  5     bban_format = '????#############'
  6     country_code = 'GB'
  7
  [end of faker/providers/bank/en_GB/__init__.py]
  </code>
  
  I need you to solve this issue by generating a single patch file that I can apply directly to this repository using git apply. Please respond with a single patch file in the following format.
  <patch>
  diff --git a/file.py b/file.py
  --- a/file.py
  +++ b/file.py
  @@ -1,27 +1,35 @@
   def euclidean(a, b):
  -    while b:
  -        a, b = b, a % b
  -    return a
  +    if b == 0:
  +        return a
  +    return euclidean(b, a % b)
   
   
   def bresenham(x0, y0, x1, y1):
       points = []
       dx = abs(x1 - x0)
       dy = abs(y1 - y0)
  -    sx = 1 if x0 < x1 else -1
  -    sy = 1 if y0 < y1 else -1
  -    err = dx - dy
  +    x, y = x0, y0
  +    sx = -1 if x0 > x1 else 1
  +    sy = -1 if y0 > y1 else 1
   
  -    while True:
  -        points.append((x0, y0))
  -        if x0 == x1 and y0 == y1:
  -            break
  -        e2 = 2 * err
  -        if e2 > -dy:
  -            err -= dy
  -            x0 += sx
  -        if e2 < dx:
  -            err += dx
  -            y0 += sy
  +    if dx > dy:
  +        err = dx / 2.0
  +        while x != x1:
  +            points.append((x, y))
  +            err -= dy
  +            if err < 0:
  +                y += sy
  +                err += dx
  +            x += sx
  +    else:
  +        err = dy / 2.0
  +        while y != y1:
  +            points.append((x, y))
  +            err -= dx
  +            if err < 0:
  +                x += sx
  +                err += dy
  +            y += sy
  +
  +    points.append((x, y))
       return points
  
  </patch>
golden_diff: diff --git a/faker/providers/bank/en_GB/__init__.py b/faker/providers/bank/en_GB/__init__.py
  --- a/faker/providers/bank/en_GB/__init__.py
  +++ b/faker/providers/bank/en_GB/__init__.py
  @@ -2,5 +2,5 @@
   
   
   class Provider(BankProvider):
  -    bban_format = '????#############'
  +    bban_format = '????##############'
       country_code = 'GB'
  
verification_info: {"golden_diff": "diff --git a/faker/providers/bank/en_GB/__init__.py b/faker/providers/bank/en_GB/__init__.py\n--- a/faker/providers/bank/en_GB/__init__.py\n+++ b/faker/providers/bank/en_GB/__init__.py\n@@ -2,5 +2,5 @@\n \n \n class Provider(BankProvider):\n-    bban_format = '????#############'\n+    bban_format = '????##############'\n     country_code = 'GB'\n", "issue": "BBAN for en_GB too short\n* Faker version: v2.0.3\r\n* OS: linux\r\n\r\nNumeric part of the en_GB BBAN needs to be 14 digits long, it currently only returns 13, failing further validation.\r\n\r\n### Steps to reproduce\r\n\r\nInvoke `fake.iban()` or `fake.bban()` with the en_GB locale, an IBAN or BBAN with 1 digit missing is returned.\r\n\r\n### Expected behavior\r\n\r\nGB ibans should be 22 chars long: https://www.xe.com/ibancalculator/sample/?ibancountry=united kingdom\r\n\r\n\n", "before_files": [{"content": "from .. import Provider as BankProvider\n\n\nclass Provider(BankProvider):\n    bban_format = '????#############'\n    country_code = 'GB'\n", "path": "faker/providers/bank/en_GB/__init__.py"}]}