You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: subsref.m
    path of file: ./repos/IRtools/Extra/prblur_tools/@transformMatrix
    
    the code of the file until where you have to start completion: function B = subsref(A, index)
%
%  Define field name indexing for transformMatrix object.
%
%               B = subsref(A, index)
%
%          This is called whenever a subscripted reference to the
%          transformMatrix object is made, such as:
%              A.fieldname, fieldname = transform, transpose
%

    
function B = subsref(A, index)
%
%  Define field name indexing for transformMatrix object.
%
%               B = subsref(A, index)
%
%          This is called whenever a subscripted reference to the
%          transformMatrix object is made, such as:
%              A.fieldname, fieldname = transform, transpose
%

%  J. Nagy  1/18/02

switch index.type
case '()'
  error('Paranthetical indexing not supported for transformMatrix object.')

case '.'
  switch index.subs
  case 'transform'
    B = A.transform;
  case 'transpose'
    B = A.transpose;
  otherwise
    error('Invalid field name.')
  end