code: def fix_e265(source, aggressive=False):  # pylint: disable=unused-argument
      
      if '#' not in source:
          # Optimization.
          return source
  
      ignored_line_numbers = multiline_string_lines(
          source,
          include_docstrings=True) | set(commented_out_code_lines(source))
  
      fixed_lines = []
      sio = io.StringIO(source)
      for (line_number, line) in enumerate(sio.readlines(), start=1):
          if (
              line.lstrip().startswith('#') and
              line_number not in ignored_line_numbers and
              not pycodestyle.noqa(line)
          ):
              indentation = _get_indentation(line)
              line = line.lstrip()
  
              # Normalize beginning if not a shebang.
              if len(line) > 1:
                  pos = next((index for index, c in enumerate(line)
                              if c != '#'))
                  if (
                      # Leave multiple spaces like '#    ' alone.
                      (line[:pos].count('#') > 1 or line[1].isalnum()) and
                      # Leave stylistic outlined blocks alone.
                      not line.rstrip().endswith('#')
                  ):
                      line = '# ' + line.lstrip('# \t')
  
              fixed_lines.append(indentation + line)
          else:
              fixed_lines.append(line)
  
      return ''.join(fixed_lines)
docs: Format block comments.