My.ecore

My.ecore

<?xml version="1.0" encoding="UTF-8"?>
<ecore:EPackage xmi:version="2.0"
    xmlns:xmi="http://www.omg.org/XMI" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:ecore="http://www.eclipse.org/emf/2002/Ecore" name="test"
    nsURI="URItest" nsPrefix="test">
  <eClassifiers xsi:type="ecore:EClass" name="Truc">
    <eOperations name="getAllMachins" upperBound="-1" eType="#//Machin">
      <eAnnotations source="http://www.eclipse.org/emf/2002/GenModel">
        <details key="body" value="EList&lt;Machin> machins = new &lt;%org.eclipse.emf.common.util.BasicEList%>&lt;Machin>(this.getAutresMachins());&#xA;machins.add(0, this.getPremierMachin());&#xA;return machins;"/>
        <details key="documentation" value="test"/>
      </eAnnotations>
    </eOperations>
    <eStructuralFeatures xsi:type="ecore:EReference" name="premierMachin" lowerBound="1"
        eType="#//Machin"/>
    <eStructuralFeatures xsi:type="ecore:EReference" name="autresMachins" lowerBound="1"
        upperBound="-1" eType="#//Machin"/>
  </eClassifiers>
  <eClassifiers xsi:type="ecore:EClass" name="Machin">
    <eStructuralFeatures xsi:type="ecore:EAttribute" name="name" lowerBound="1" eType="ecore:EDataType http://www.eclipse.org/emf/2002/Ecore#//EString"
        iD="true"/>
  </eClassifiers>
</ecore:EPackage>

Small example of metamodel with method implementation