graphdb/src/main/java/com/orientechnologies/orient/graph/graphml/OGraphMLReader.java
public void inputGraph(final Graph inputGraph, final String filename) throws IOException {
    inputGraph(inputGraph, filename, batchSize, vertexIdKey, edgeIdKey, edgeLabelKey);
  }
public void inputGraph(final Graph inputGraph, final String filename) throws IOException {
    inputGraph(inputGraph, filename, batchSize, vertexIdKey, edgeIdKey, edgeLabelKey);
  }
Input the GraphML stream data into the graph. In practice, usually the provided graph is empty.

@param inputGraph
the graph to populate with the GraphML data
@param filename
name of a file containing GraphML data
@throws IOException
thrown when the GraphML data is not correctly formatted