private static String getStringType(final Object object) {
        if (object instanceof String)
            return GraphMLTokens.STRING;
        else if (object instanceof Integer)
            return GraphMLTokens.INT;
        else if (object instanceof Long)
            return GraphMLTokens.LONG;
        else if (object instanceof Float)
            return GraphMLTokens.FLOAT;
        else if (object instanceof Double)
            return GraphMLTokens.DOUBLE;
        else if (object instanceof Boolean)
            return GraphMLTokens.BOOLEAN;
        else
            return GraphMLTokens.STRING;
        }
Write the data in a Graph to a GraphML OutputStream.

@param outputStream the GraphML OutputStream to write the Graph data to
@throws IOException thrown if there is an error generating the GraphML data
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/structure/io/graphml/GraphMLWriter.java