\documentclass{article}
\usepackage[a3paper]{geometry}
\usepackage[cm]{fullpage}
\usepackage[utf8]{inputenc}
\usepackage{listings}
\usepackage{verbatim}
\usepackage[english]{babel}
\usepackage{tikz}
\usetikzlibrary{shapes,arrows,backgrounds,calc}
\begin{document}
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%}}}
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    column sep=2mm,minimum width=.875cm, minimum height=1cm]
{
\node [header] (1_1) {Moose Attributes};\\\node [pointer] (2_1) {read-write / read only}; & 
	\node [mnemonic-block] (2_2) {\begin{lstlisting}[language=Perl]
has 'attr' => {is => 'rw'}
has 'attr' => {is => 'ro'}
\end{lstlisting}};\\\node [pointer] (3_1) {Accessor methods}; & 
	\node [mnemonic-block] (3_2) {\begin{lstlisting}[language=Perl]
has 'attr' => {reader => 'get_attr',}
has 'attr' => {writer => 'set_attr',}
\end{lstlisting}};\\\node [pointer] (4_1) {Predicate method}; & 
	\node [mnemonic-block] (4_2) {\begin{lstlisting}[language=Perl]
has 'attr' => {predicate => 'has_attr'}
\end{lstlisting}
		}; & 
	\node [comment] (4_3) {Tells you whether or not a given attribute is currently set};\\\node [pointer] (5_1) {Cleaner method}; & 
	\node [mnemonic-block] (5_2) {\begin{lstlisting}[language=Perl]
has 'attr' => {cleaner => 'clean_attr'}
\end{lstlisting}}; & 
	\node [comment] (5_3) {Unsets the attribute};\\\node [pointer] (6_1) {Required}; & 
	\node [mnemonic-block] (6_2) {\begin{lstlisting}[language=Perl]
has 'attr' => {required => 1}
\end{lstlisting}};\\\node [pointer] (7_1) {Lazy}; & 
	\node [mnemonic-block] (7_2) {\begin{lstlisting}[language=Perl]
has 'attr' => {lazy => 1}
\end{lstlisting}
		}; & 
	\node [comment] (7_3) {When lazy is true, the default is not generated until the reader method is called};\\\node [pointer] (8_1) {Constructor parameters}; & 
	\node [mnemonic-block] (8_2) {\begin{lstlisting}[language=Perl]
has 'attr' => {init_arg => 'new_name'}
\end{lstlisting}
	}; & 
	\node [comment] (8_3) {
		Use a different name for the constructor parameter for this attribute.
	};\\\node [pointer] (9_1) {Weak references}; & 
	\node [mnemonic-block] (9_2) {\begin{lstlisting}[language=Perl]
has 'attr' => {weak_ref => 1}
\end{lstlisting}
	}; & 
	\node [comment] (9_3) {
		If you set the weak\_ref option to a true value, then it will call Scalar::Util::weaken whenever the attribute is set
	};\\\node [pointer] (10_1) {Trigger}; & 
	\node [mnemonic-block] (10_2) {\begin{lstlisting}[language=Perl]
has 'attr' => {trigger => \&attr_set}
\end{lstlisting}
	}; & 
	\node [comment] (10_3) {subroutine that is called whenever the attribute is set};\\\node [pointer] (11_1) {Attribute type}; & 
	\node [mnemonic-block] (11_2) {\begin{lstlisting}[language=Perl]
has 'attr' => {isa => 'Str',}
has 'attr' => {isa => 'MyApp::Weapon',}
\end{lstlisting}
	};\\\node [pointer] (12_1) {Documentation}; & 
	\node [mnemonic-block] (12_2) {\begin{lstlisting}[language=Perl]
has 'attr' => {documentation => q{Some text}}
\end{lstlisting}
		};\\
};
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\end{document}