\begin{tikzpicture}

\tikzstyle{abstract}=[rectangle, draw=black, rounded corners, fill=white, drop shadow, text centered, anchor=north, text width=6cm]
        
%nodes
\node (Vector) [abstract, rectangle split, rectangle split parts=3]
{
\textbf{Vector}
\nodepart{second}
\begin{lstlisting}[frame=none,basicstyle=\scriptsize\ttfamily]
typedef value_type;
typedef size_type;
\end{lstlisting}
\nodepart{third}
\begin{lstlisting}[frame=none,basicstyle=\scriptsize\ttfamily]
           Vector(size_type);
           Vector(Vector);
void       axpy(value_type,Vector);
void       axpby(value_type,Vector);
void       copy(Vector);
value_type dot(Vector);
Vector*    duplicate();
void       fill(value_type);
value_type nrmi();
value_type nrm2();
void       scal(vale_type);
size_type  size();
\end{lstlisting}
};

\node (Matrix) [abstract, rectangle split, rectangle split parts=3, below right=0cm and 0.4cm of Vector.north east]
{
\textbf{Matrix}
\nodepart{second}
\begin{lstlisting}[frame=none,basicstyle=\scriptsize\ttfamily]
typedef vector_type;
\end{lstlisting}
\nodepart{third}
\begin{lstlisting}[frame=none,basicstyle=\scriptsize\ttfamily]
void mult(vector_type);
\end{lstlisting}
};

\node (Solver) [abstract, rectangle split, rectangle split parts=3, below=of Vector]
{
\textbf{EqSolver}
\nodepart{second}
\begin{lstlisting}[frame=none,basicstyle=\scriptsize\ttfamily]
typedef vector_type;
typedef matrix_type;
typedef monitor_type;
typedef preconditioner_type;
\end{lstlisting}
\nodepart{third}
\begin{lstlisting}[frame=none,basicstyle=\scriptsize\ttfamily]
     EqSolver(matrix_type
             ,monitor_type);
void solve(vector_type,vector_type);
void set_preconditioner(preconditioner_type);
\end{lstlisting}
};

\node (Preconditioner) [abstract, rectangle split, rectangle split parts=3, below=of Matrix]
{
\textbf{Preconditioner}
\nodepart{second}
\begin{lstlisting}[frame=none,basicstyle=\scriptsize\ttfamily]
typedef vector_type;
typedef matrix_type;
typedef monitor_type;
\end{lstlisting}
\nodepart{third}
\begin{lstlisting}[frame=none,basicstyle=\scriptsize\ttfamily]
     Preconditioner(matrix_type
                   ,monitor_type);
void operator()(vector_type,vector_type)
\end{lstlisting}
};

\node (TimeIntegrator) [abstract, rectangle split, rectangle split parts=2, below=of Preconditioner]
{
\textbf{TimeIntegrator}
\nodepart{second}
%\nodepart{third}
\begin{lstlisting}[frame=none,basicstyle=\scriptsize\ttfamily]
template <typename rhs_type
        , typename vector_type
        , typename value_type>
void operator()(rhs_type
               ,vector_type
               ,value_type
               ,value_type
               ,value_type);
\end{lstlisting}
};

\end{tikzpicture}