function tex_string = getTeXString(a_doc, props)
% getTeXString - Returns the TeX representation for the document.
% tex_string = getTeXString(a_doc, props)
% This is an abstract placeholder for this method. It specifies what this
% method should do in the subclasses that implement it. This method should
% create all the auxiliary files needed by the document. The generated tex_string
% should be ready to be visualized.
% a_doc: A tests_db object.
% props: A structure with any optional properties.
% tex_string: A string that contains TeX commands, which upon writing to a file,
% can be interpreted by the TeX engine to produce a document.
% doc_plot has an overloaded getTeXString method:
% >> tex_string = getTeXString(a_doc_plot)
% >> string2File(tex_string, 'my_doc.tex')
% then my_doc.tex can be used by including from a valid LaTeX document.
% See also: doc_generate, doc_plot
% Author: Cengiz Gunay <firstname.lastname@example.org>, 2006/01/17
% Copyright (c) 2007 Cengiz Gunay <email@example.com>.
% This work is licensed under the Academic Free License ("AFL")
% v. 3.0. To view a copy of this license, please look at the COPYING
% file distributed with this software or visit
tex_string = a_doc.text;