xbar 堆叠中的标签未显示

Question

我使用的是pgfplots1.7。下图中未显示条形的标签。

\documentclass{article}
\usepackage{pgfplots}
%\usepackage{pgfplotstable}
\pgfplotsset{compat=1.7}

\begin{document}

    \begin{tikzpicture}
      \begin{axis}[xbar stacked,
        clip=false,
        enlarge y limits=0.05,
        tick label style={font=\footnotesize},
        label style={font=\footnotesize},
        width=7cm,
        height=6.5cm,
        bar width=3mm,
        xlabel={Percentage of verification tasks for which a tool was chosen, \%},
        nodes near coords,
        symbolic y coords={Overall,Sequentialized,Recursive,MemorySafety,HeapManipulation,DeviceDrivers64,ProductLines,Loops,ControlFlowInteger,ControlFlow,Concurrency,BitVectors},
        ytick={Overall,Sequentialized,Recursive,MemorySafety,HeapManipulation,DeviceDrivers64,ProductLines,Loops,ControlFlowInteger,ControlFlow,Concurrency,BitVectors},
        ]
        \addplot+[point meta=explicit symbolic] coordinates {
          (27.04,Overall) [cb]
          (36.36,Sequentialized) [cb]
          (89.89,Recursive) [cb]
          (53.88,MemorySafety) [cb]
          (41.90,HeapManipulation) [cb]
          (30.84,DeviceDrivers64) [cb]
          (0,ProductLines) [cb]
          (57.63,Loops) [cb]
          (23.80,ControlFlowInteger) [cb]
          (12.37,ControlFlow) [cb]
          (16.61,Concurrency) [cb]
          (42.02,BitVectors) [cb]
        };

      \end{axis}
    \end{tikzpicture}

\end{document}

这就是我得到的。

不过，我需要在每个条形内添加“cb”标签。非常感谢！