code: def analyze(self, rows):
          
          transposed = zip(*rows)
          checks = self.get_checks()
          column_types = []
          for i, column in enumerate(transposed):
              # Remove any empty values.
              col_vals = [val for val in column if val != '']
              for check in checks:
                  results = set(check(val) for val in col_vals)
                  if all(results):
                      column_types.append(check.field())
                      break
  
          return column_types
docs: Analyze the given rows and try to determine the type of value stored.
          :param list rows: A list-of-lists containing one or more rows from a
                            csv file.
          :returns: A list of peewee Field objects for each column in the CSV.