test number zero : default constructor and string converter
symtensor0 = class=SymmetricTensor implementation=class=TensorImplementation name=Unnamed rows=0 columns=0 sheets=0 values=[]
test number one : constructor with size, operator() and string converter
symtensor1 = class=SymmetricTensor implementation=class=TensorImplementation name=symtensor1 rows=2 columns=2 sheets=3 values=[1,2,0,3,4,5,0,6,7,8,0,9]
symtensor1 = sheet #0
[[ 1 2 ]
 [ 2 3 ]]
sheet #1
[[ 4 5 ]
 [ 5 6 ]]
sheet #2
[[ 7 8 ]
 [ 8 9 ]]
symtensor1's values = 1,2,2,3,4,5,5,6,7,8,8,9
test number two : copy constructor and string converter
symtensor2 = class=SymmetricTensor implementation=class=TensorImplementation name=symtensor1 rows=2 columns=2 sheets=3 values=[1,2,2,3,4,5,5,6,7,8,8,9]
symtensor2 = sheet #0
[[ 1 2 ]
 [ 2 3 ]]
sheet #1
[[ 4 5 ]
 [ 5 6 ]]
sheet #2
[[ 7 8 ]
 [ 8 9 ]]
test number three : get dimensions methods
symtensor1's nbRows = 2
symtensor1's nbColumns = 2
symtensor1's nbSheets = 3
test number four : assignment method
symtensor3 = class=SymmetricTensor implementation=class=TensorImplementation name=symtensor1 rows=2 columns=2 sheets=3 values=[1,2,2,3,4,5,5,6,7,8,8,9]
symtensor3 = sheet #0
[[ 1 2 ]
 [ 2 3 ]]
sheet #1
[[ 4 5 ]
 [ 5 6 ]]
sheet #2
[[ 7 8 ]
 [ 8 9 ]]
test number five : isEmpty method
symtensor1 is empty = false
symtensor0 is empty = true
symtensor5 is empty = true
symtensor6 is empty = true
symtensor1 = class=SymmetricTensor implementation=class=TensorImplementation name=symtensor1 rows=2 columns=2 sheets=3 values=[1,2,2,3,4,5,5,6,7,8,8,9]
symtensor1.getSheet(1) = class=SymmetricMatrix dimension=2 implementation=class=MatrixImplementation name=Unnamed rows=2 columns=2 values=[4,5,5,6]
sheet2 = class=SymmetricMatrix dimension=2 implementation=class=MatrixImplementation name=Unnamed rows=2 columns=2 values=[0.4,0.5,0,0.6]
symtensor1 = class=SymmetricTensor implementation=class=TensorImplementation name=symtensor1 rows=2 columns=2 sheets=3 values=[1,2,2,3,0.4,0.5,0.5,0.6,7,8,8,9]
symtensor1 = sheet #0
[[ 1   2   ]
 [ 2   3   ]]
sheet #1
[[ 0.4 0.5 ]
 [ 0.5 0.6 ]]
sheet #2
[[ 7   8   ]
 [ 8   9   ]]
