code: def _validate_sizes(n, m):
      if n < 1 or not isinstance(n, numbers.Integral):
          raise ValueError(
              "Invalid number of CZT data "
              f"points ({n}) specified. "
              "n must be positive and integer type."
          )
  
      if m is None:
          m = n
      elif m < 1 or not isinstance(m, numbers.Integral):
          raise ValueError(
              "Invalid number of CZT output "
              f"points ({m}) specified. "
              "m must be positive and integer type."
          )
  
      return m
  
file_path: scipy/scipy/signal/_czt.py
imports: import cmath
  import numbers
  import numpy
  from numpy import pi, arange
  from scipy.fft import fft, ifft, next_fast_len
label_desc: Use image node_id 1 for calling a global function with example usage: _validate_sizes(n, m) and returns: m