code: def fit(self, input_data):
      f_x = input_data.idx
      f_y = input_data.features
      self.coefs = np.polyfit(f_x, f_y, deg=self.degree)
  
      return self.coefs
  
file_path: FEDOT/fedot/core/operations/evaluation/operation_implementations/models/ts_implementations/poly.py
imports: from copy import copy
  from typing import Optional
  import numpy
  from fedot.core.data.data import InputData, OutputData
  from fedot.core.operations.evaluation.operation_implementations.data_operations.ts_transformations import ts_to_table
  from fedot.core.operations.evaluation.operation_implementations.implementation_interfaces import ModelImplementation
  from fedot.core.operations.operation_parameters import OperationParameters
  from fedot.core.repository.dataset_types import DataTypesEnum
label_desc: Use image node_id 4 for calling the PolyfitImplementation obj's underlying member method code with example usage: obj.fit(input_data) and returns: self