input: 
  def match_numeric_strings(pattern: str, string: str) -> bool:
      """ Matches a given string against a regular expression pattern that should only match numeric strings.
      Returns True if the string is a valid numeric string, otherwise returns False.
      >>> match_numeric_strings(pattern='^[0-9]+$', string='123456789')
      True
      >>> match_numeric_strings(pattern='^[0-9]+$', string='abc123')
      False
      """
      import re
      result = re.match(pattern, string)
      return bool(result)
  
output:     import re
      result = re.match(pattern, string)
      return bool(result)