### Question:
FieldMapping implements IFieldMapping { public void setSourceFieldName( String sourceFieldName ) { this.sourceFieldName = sourceFieldName; } FieldMapping();  FieldMapping( String sourceFieldName, String targetFieldName ); @Override String getSourceFieldName(); @Override String getTargetFieldName(); void setSourceFieldName( String sourceFieldName ); void setTargetFieldName( String targetFieldName ); @Override boolean equals( Object o ); @Override int hashCode();  }### Answer:
@Test public void testSetSourceFieldName() throws Exception { mapping = new FieldMapping(); assertNull( mapping.getSourceFieldName() ); mapping.setSourceFieldName( "from" ); assertEquals( "from", mapping.getSourceFieldName() ); }