public static boolean isSynthetic(MethodNode method) {
    return method.isSynthetic() || (method.getModifiers() & Opcodes.ACC_SYNTHETIC) != 0;
  }
Checks whether the given statement represents a data table separator.
A data table separator is an expression statement consisting of a
variable expression whose name is two or more underscores and
that does not reference any existing variable, parameter or field.

@param stat the statement to check for being a data table separator
@return whether the given statement is a data table separator
spock-core/src/main/java/org/spockframework/compiler/AstUtil.java