graphdb/src/main/java/com/tinkerpop/blueprints/impls/orient/OrientVertex.java
public static String getConnectionFieldName(final Direction iDirection, final String iClassName,
      final boolean useVertexFieldsForEdgeLabels) {
    if (iDirection == null || iDirection == Direction.BOTH)
      throw new IllegalArgumentException("Direction not valid");

    if (useVertexFieldsForEdgeLabels) {
      // PREFIX "out_" or "in_" TO THE FIELD NAME
      final String prefix = iDirection == Direction.OUT ? CONNECTION_OUT_PREFIX : CONNECTION_IN_PREFIX;
      if (iClassName == null || iClassName.isEmpty() || iClassName.equals(OrientEdgeType.CLASS_NAME))
        return prefix;

      return prefix + iClassName;
    } else
      // "out" or "in"
      return iDirection == Direction.OUT ? OrientBaseGraph.CONNECTION_OUT : OrientBaseGraph.CONNECTION_IN;
  }
public static String getConnectionFieldName(final Direction iDirection, final String iClassName,
      final boolean useVertexFieldsForEdgeLabels) {
    if (iDirection == null || iDirection == Direction.BOTH)
      throw new IllegalArgumentException("Direction not valid");

    if (useVertexFieldsForEdgeLabels) {
      // PREFIX "out_" or "in_" TO THE FIELD NAME
      final String prefix = iDirection == Direction.OUT ? CONNECTION_OUT_PREFIX : CONNECTION_IN_PREFIX;
      if (iClassName == null || iClassName.isEmpty() || iClassName.equals(OrientEdgeType.CLASS_NAME))
        return prefix;

      return prefix + iClassName;
    } else
      // "out" or "in"
      return iDirection == Direction.OUT ? OrientBaseGraph.CONNECTION_OUT : OrientBaseGraph.CONNECTION_IN;
  }
(Internal only) Returns the field name used for the relationship.

@param iDirection                   Direction between IN, OUT or BOTH
@param iClassName                   Class name if any
@param useVertexFieldsForEdgeLabels Graph setting about using the edge label as vertex's field