code: def PowerlawGuinierPorodConst(q, A, alpha, G, Rg, beta, C):
      
      return PowerlawPlusConstant(q, A, alpha, C) + GuinierPorod(q, G, Rg, beta)
docs: Sum of a Power-law, a Guinier-Porod curve and a constant.
  
      Inputs:
      -------
          ``q``: independent variable (momentum transfer)
          ``A``: scaling factor of the power-law
          ``alpha``: power-law exponent
          ``G``: scaling factor of the Guinier-Porod curve
          ``Rg``: Radius of gyration
          ``beta``: power-law exponent of the Guinier-Porod curve
          ``C``: additive constant
  
      Formula:
      --------
          ``A*q^alpha + GuinierPorod(q,G,Rg,beta) + C``